Guide to the Secure Configuration of Red Hat Enterprise Linux 8

with profile VPP - Protection Profile for Virtualization v. 1.0 for Red Hat Enterprise Linux Hypervisor (RHELH)
This compliance profile reflects the core set of security related configuration settings for deployment of Red Hat Enterprise Linux Hypervisor (RHELH) 7.x into U.S. Defense, Intelligence, and Civilian agencies. Development partners and sponsors include the U.S. National Institute of Standards and Technology (NIST), U.S. Department of Defense, the National Security Agency, and Red Hat. This baseline implements configuration requirements from the following sources: - Committee on National Security Systems Instruction No. 1253 (CNSSI 1253) - NIST 800-53 control selections for MODERATE impact systems (NIST 800-53) - U.S. Government Configuration Baseline (USGCB) - NIAP Protection Profile for Virtualization v1.0 (VPP v1.0) For any differing configuration requirements, e.g. password lengths, the stricter security setting was chosen. Security Requirement Traceability Guides (RTMs) and sample System Security Configuration Guides are provided via the scap-security-guide-docs package. This profile reflects U.S. Government consensus content and is developed through the ComplianceAsCode project, championed by the National Security Agency. Except for differences in formatting to accommodate publishing processes, this profile mirrors ComplianceAsCode content as minor divergences, such as bugfixes, work through the consensus and release processes.
This guide presents a catalog of security-relevant configuration settings for Red Hat Enterprise Linux 8. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the scap-security-guide package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.

Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.
Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.

Profile Information

Profile TitleVPP - Protection Profile for Virtualization v. 1.0 for Red Hat Enterprise Linux Hypervisor (RHELH)
Profile IDxccdf_org.ssgproject.content_profile_rhelh-vpp

CPE Platforms

  • cpe:/o:redhat:enterprise_linux:8

Revision History

Current version: 0.1.51

  • draft (as of 2020-07-20)

Table of Contents

  1. System Settings
    1. Account and Access Control
    2. System Accounting with auditd
    3. Installing and Maintaining Software
    4. GRUB2 bootloader configuration
    5. SELinux
    6. File Permissions and Masks
    7. Network Configuration and Firewalls
  2. Services
    1. SSH Server
    2. Base Services
    3. Application Whitelisting Daemon
    4. USBGuard daemon
    5. Network Time Protocol
    6. Kerberos
    7. NFS and RPC
    8. Mail Server Software
    9. Hardware RNG Entropy Gatherer Daemon

Checklist

Group   Guide to the Secure Configuration of Red Hat Enterprise Linux 8   Group contains 61 groups and 199 rules
Group   System Settings   Group contains 49 groups and 173 rules

[ref]   Contains rules that check correct system settings.

Group   Account and Access Control   Group contains 13 groups and 29 rules

[ref]   In traditional Unix security, if an attacker gains shell access to a certain login account, they can perform any action or access any file to which that account has access. Therefore, making it more difficult for unauthorized people to gain shell access to accounts, particularly to privileged accounts, is a necessary part of securing a system. This section introduces mechanisms for restricting access to accounts under Red Hat Enterprise Linux 8.

Group   Protect Accounts by Configuring PAM   Group contains 3 groups and 12 rules

[ref]   PAM, or Pluggable Authentication Modules, is a system which implements modular authentication for Linux programs. PAM provides a flexible and configurable architecture for authentication, and it should be configured to minimize exposure to unnecessary risk. This section contains guidance on how to accomplish that.

PAM is implemented as a set of shared objects which are loaded and invoked whenever an application wishes to authenticate a user. Typically, the application must be running as root in order to take advantage of PAM, because PAM's modules often need to be able to access sensitive stores of account information, such as /etc/shadow. Traditional privileged network listeners (e.g. sshd) or SUID programs (e.g. sudo) already meet this requirement. An SUID root application, userhelper, is provided so that programs which are not SUID or privileged themselves can still take advantage of PAM.

PAM looks in the directory /etc/pam.d for application-specific configuration information. For instance, if the program login attempts to authenticate a user, then PAM's libraries follow the instructions in the file /etc/pam.d/login to determine what actions should be taken.

One very important file in /etc/pam.d is /etc/pam.d/system-auth. This file, which is included by many other PAM configuration files, defines 'default' system authentication measures. Modifying this file is a good way to make far-reaching authentication changes, for instance when implementing a centralized authentication service.

Warning:  Be careful when making changes to PAM's configuration files. The syntax for these files is complex, and modifications can have unexpected consequences. The default configurations shipped with applications should be sufficient for most users.
Warning:  Running authconfig or system-config-authentication will re-write the PAM configuration files, destroying any manually made changes and replacing them with a series of system defaults. One reference to the configuration file syntax can be found at http://www.linux-pam.org/Linux-PAM-html/sag-configuration-file.html.
Group   Set Password Quality Requirements   Group contains 1 group and 8 rules

[ref]   The default pam_pwquality PAM module provides strength checking for passwords. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of at least a certain length, are not the previous password reversed, and are not simply a change of case from the previous password. It can also require passwords to be in certain character classes. The pam_pwquality module is the preferred way of configuring password requirements.

The pam_cracklib PAM module can also provide strength checking for passwords as the pam_pwquality module. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of at least a certain length, are not the previous password reversed, and are not simply a change of case from the previous password. It can also require passwords to be in certain character classes.

The man pages pam_pwquality(8) and pam_cracklib(8) provide information on the capabilities and configuration of each.

Group   Set Password Quality Requirements with pam_pwquality   Group contains 8 rules

[ref]   The pam_pwquality PAM module can be configured to meet requirements for a variety of policies.

For example, to configure pam_pwquality to require at least one uppercase character, lowercase character, digit, and other (special) character, make sure that pam_pwquality exists in /etc/pam.d/system-auth:

password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth. Next, modify the settings in /etc/security/pwquality.conf to match the following:
difok = 4
minlen = 14
dcredit = -1
ucredit = -1
lcredit = -1
ocredit = -1
maxrepeat = 3
The arguments can be modified to ensure compliance with your organization's security policy. Discussion of each parameter follows.

Rule   Ensure PAM Enforces Password Requirements - Minimum Digit Characters   [ref]

The pam_pwquality module's dcredit parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_pwquality will grant +1 additional length credit for each digit. Modify the dcredit setting in /etc/security/pwquality.conf to require the use of a digit in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_dcredit
Identifiers and References

Identifiers:  CCE-80653-9

References:  6.3.2, 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000194, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000071-GPOS-00039, SRG-OS-000071-VMM-000380



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_dcredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^dcredit' $var_password_pam_dcredit 'CCE-80653-9' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_dcredit # promote to variable
  set_fact:
    var_password_pam_dcredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable dcredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*dcredit
    line: dcredit = {{ var_password_pam_dcredit }}
  tags:
    - CCE-80653-9
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_dcredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Minimum Special Characters   [ref]

The pam_pwquality module's ocredit= parameter controls requirements for usage of special (or "other") characters in a password. When set to a negative number, any password will be required to contain that many special characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each special character. Modify the ocredit setting in /etc/security/pwquality.conf to equal -1 to require use of a special character in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possble combinations that need to be tested before the password is compromised. Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_ocredit
Identifiers and References

Identifiers:  CCE-80663-8

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-001619, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000266-GPOS-00101, SRG-OS-000266-VMM-000940



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_ocredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^ocredit' $var_password_pam_ocredit 'CCE-80663-8' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_ocredit # promote to variable
  set_fact:
    var_password_pam_ocredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable ocredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*ocredit
    line: ocredit = {{ var_password_pam_ocredit }}
  tags:
    - CCE-80663-8
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - accounts_password_pam_ocredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters   [ref]

The pam_pwquality module's ucredit= parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each uppercase character. Modify the ucredit setting in /etc/security/pwquality.conf to require the use of an uppercase character in passwords.

Rationale:

Use of a complex password helps to increase the time and resources reuiqred to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_ucredit
Identifiers and References

Identifiers:  CCE-80665-3

References:  6.3.2, 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000069-GPOS-00037, SRG-OS-000069-VMM-000360



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_ucredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^ucredit' $var_password_pam_ucredit 'CCE-80665-3' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_ucredit # promote to variable
  set_fact:
    var_password_pam_ucredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable ucredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*ucredit
    line: ucredit = {{ var_password_pam_ucredit }}
  tags:
    - CCE-80665-3
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_ucredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Minimum Length   [ref]

The pam_pwquality module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=12 after pam_pwquality to set minimum password length requirements.

Rationale:

The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromose the password.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
Identifiers and References

Identifiers:  CCE-80656-2

References:  6.3.2, 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000205, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000078-GPOS-00046, SRG-OS-000072-VMM-000390, SRG-OS-000078-VMM-000450



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_minlen="12"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^minlen' $var_password_pam_minlen 'CCE-80656-2' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_minlen # promote to variable
  set_fact:
    var_password_pam_minlen: !!str 12
  tags:
    - always

- name: Ensure PAM variable minlen is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*minlen
    line: minlen = {{ var_password_pam_minlen }}
  tags:
    - CCE-80656-2
    - CJIS-5.6.2.1.1
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_minlen
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Set Password Maximum Consecutive Repeating Characters   [ref]

The pam_pwquality module's maxrepeat parameter controls requirements for consecutive repeating characters. When set to a positive number, it will reject passwords which contain more than that number of consecutive characters. Modify the maxrepeat setting in /etc/security/pwquality.conf to equal 3 to prevent a run of (3 + 1) or more identical characters.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Passwords with excessive repeating characters may be more vulnerable to password-guessing attacks.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_maxrepeat
Identifiers and References

Identifiers:  CCE-82066-2

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_maxrepeat="3"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^maxrepeat' $var_password_pam_maxrepeat 'CCE-82066-2' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_maxrepeat # promote to variable
  set_fact:
    var_password_pam_maxrepeat: !!str 3
  tags:
    - always

- name: Ensure PAM variable maxrepeat is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*maxrepeat
    line: maxrepeat = {{ var_password_pam_maxrepeat }}
  tags:
    - CCE-82066-2
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - accounts_password_pam_maxrepeat
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Minimum Different Characters   [ref]

The pam_pwquality module's difok parameter sets the number of characters in a password that must not be present in and old password during a password change.

Modify the difok setting in /etc/security/pwquality.conf to equal 4 to require differing characters when changing passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute–force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Requiring a minimum number of different characters during password changes ensures that newly changed passwords should not resemble previously compromised ones. Note that passwords which are changed on compromised systems will still be compromised, however.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_difok
Identifiers and References

Identifiers:  CCE-80654-7

References:  1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(b), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040, SRG-OS-000072-VMM-000390



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_difok="4"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^difok' $var_password_pam_difok 'CCE-80654-7' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_difok # promote to variable
  set_fact:
    var_password_pam_difok: !!str 4
  tags:
    - always

- name: Ensure PAM variable difok is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*difok
    line: difok = {{ var_password_pam_difok }}
  tags:
    - CCE-80654-7
    - CJIS-5.6.2.1.1
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(b)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - accounts_password_pam_difok
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters   [ref]

The pam_pwquality module's lcredit parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each lowercase character. Modify the lcredit setting in /etc/security/pwquality.conf to require the use of a lowercase character in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possble combinations that need to be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_lcredit
Identifiers and References

Identifiers:  CCE-80655-4

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000070-GPOS-00038, SRG-OS-000070-VMM-000370



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_lcredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^lcredit' $var_password_pam_lcredit 'CCE-80655-4' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_lcredit # promote to variable
  set_fact:
    var_password_pam_lcredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable lcredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*lcredit
    line: lcredit = {{ var_password_pam_lcredit }}
  tags:
    - CCE-80655-4
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_lcredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Maximum Consecutive Repeating Characters from Same Character Class   [ref]

The pam_pwquality module's maxclassrepeat parameter controls requirements for consecutive repeating characters from the same character class. When set to a positive number, it will reject passwords which contain more than that number of consecutive characters from the same character class. Modify the maxclassrepeat setting in /etc/security/pwquality.conf to equal 4 to prevent a run of (4 + 1) or more identical characters.

Rationale:

Use of a complex password helps to increase the time and resources required to comrpomise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that need to be tested before the password is compromised.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_maxclassrepeat
Identifiers and References

Identifiers:  CCE-81034-1

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040



Complexity:low
Disruption:low
Strategy:restrict

var_password_pam_maxclassrepeat="4"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^maxclassrepeat' $var_password_pam_maxclassrepeat 'CCE-81034-1' '%s = %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_password_pam_maxclassrepeat # promote to variable
  set_fact:
    var_password_pam_maxclassrepeat: !!str 4
  tags:
    - always

- name: Ensure PAM variable maxclassrepeat is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*maxclassrepeat
    line: maxclassrepeat = {{ var_password_pam_maxclassrepeat }}
  tags:
    - CCE-81034-1
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(4)
    - NIST-800-53-IA-5(c)
    - accounts_password_pam_maxclassrepeat
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
Group   Set Lockouts for Failed Password Attempts   Group contains 4 rules

[ref]   The pam_faillock PAM module provides the capability to lock out user accounts after a number of failed login attempts. Its documentation is available in /usr/share/doc/pam-VERSION/txts/README.pam_faillock.

Warning:  Locking out user accounts presents the risk of a denial-of-service attack. The lockout policy must weigh whether the risk of such a denial-of-service attack outweighs the benefits of thwarting password guessing attacks.

Rule   Limit Password Reuse   [ref]

Do not allow users to reuse recent passwords. This can be accomplished by using the remember option for the pam_unix or pam_pwhistory PAM modules.

In the file /etc/pam.d/system-auth, append remember=5 to the line which refers to the pam_unix.so or pam_pwhistory.somodule, as shown below:

  • for the pam_unix.so case:
    password sufficient pam_unix.so ...existing_options... remember=5
  • for the pam_pwhistory.so case:
    password requisite pam_pwhistory.so ...existing_options... remember=5
The DoD STIG requirement is 5 passwords.

Rationale:

Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_unix_remember
Identifiers and References

Identifiers:  CCE-80666-1

References:  5.3.3, 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, CCI-000200, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(e), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.5, SRG-OS-000077-GPOS-00045, SRG-OS-000077-VMM-000440




var_password_pam_unix_remember="5"

AUTH_FILES[0]="/etc/pam.d/system-auth"
AUTH_FILES[1]="/etc/pam.d/password-auth"

for pamFile in "${AUTH_FILES[@]}"
do
	if grep -q "remember=" $pamFile; then
		sed -i --follow-symlinks "s/\(^password.*sufficient.*pam_unix.so.*\)\(\(remember *= *\)[^ $]*\)/\1remember=$var_password_pam_unix_remember/" $pamFile
	else
		sed -i --follow-symlinks "/^password[[:space:]]\+sufficient[[:space:]]\+pam_unix.so/ s/$/ remember=$var_password_pam_unix_remember/" $pamFile
	fi
done


Complexity:low
Disruption:medium
Strategy:configure
- name: XCCDF Value var_password_pam_unix_remember # promote to variable
  set_fact:
    var_password_pam_unix_remember: !!str 5
  tags:
    - always

- name: Do not allow users to reuse recent passwords - system-auth (change)
  replace:
    dest: /etc/pam.d/system-auth
    follow: true
    regexp: ^(password\s+sufficient\s+pam_unix\.so\s.*remember\s*=\s*)(\S+)(.*)$
    replace: \g<1>{{ var_password_pam_unix_remember }}\g<3>
  tags:
    - CCE-80666-1
    - CJIS-5.6.2.1.1
    - NIST-800-171-3.5.8
    - NIST-800-53-IA-5(1)(e)
    - NIST-800-53-IA-5(f)
    - PCI-DSS-Req-8.2.5
    - accounts_password_pam_unix_remember
    - configure_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed

- name: Do not allow users to reuse recent passwords - system-auth (add)
  replace:
    dest: /etc/pam.d/system-auth
    follow: true
    regexp: ^password\s+sufficient\s+pam_unix\.so\s(?!.*remember\s*=\s*).*$
    replace: \g<0> remember={{ var_password_pam_unix_remember }}
  tags:
    - CCE-80666-1
    - CJIS-5.6.2.1.1
    - NIST-800-171-3.5.8
    - NIST-800-53-IA-5(1)(e)
    - NIST-800-53-IA-5(f)
    - PCI-DSS-Req-8.2.5
    - accounts_password_pam_unix_remember
    - configure_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed

Rule   Set Interval For Counting Failed Password Attempts   [ref]

Utilizing pam_faillock.so, the fail_interval directive configures the system to lock out an account after a number of incorrect login attempts within a specified time period. Modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • Add the following line immediately before the pam_unix.so statement in the AUTH section:
    auth required pam_faillock.so preauth silent deny=3 unlock_time=0 fail_interval=900
  • Add the following line immediately after the pam_unix.so statement in the AUTH section:
    auth [default=die] pam_faillock.so authfail deny=3 unlock_time=0 fail_interval=900
    
  • Add the following line immediately before the pam_unix.so statement in the ACCOUNT section:
    account required pam_faillock.so

Rationale:

By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_interval
Identifiers and References

Identifiers:  CCE-80669-5

References:  1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, CCI-000044, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SRG-OS-000021-VMM-000050




var_accounts_passwords_pam_faillock_fail_interval="900"

AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

for pam_file in "${AUTH_FILES[@]}"
do
    # is auth required pam_faillock.so preauth present?
    if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*'"fail_interval"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock.so.*preauth.*silent.*\)\('"fail_interval"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock.so.*preauth.*silent.*/ s/$/ '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        fi
    # auth required pam_faillock.so preauth is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/i auth        required      pam_faillock.so preauth silent '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval" "$pam_file"
    fi
    # is auth default pam_faillock.so authfail present?
    if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*'"fail_interval"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\('"fail_interval"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*[default=die].*pam_faillock.so.*authfail.*/ s/$/ '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        fi
    # auth default pam_faillock.so authfail is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/a auth        [default=die] pam_faillock.so authfail '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval" "$pam_file"
    fi
    if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
        sed -E -i --follow-symlinks '/^\s*account\s*required\s*pam_unix.so/i account     required      pam_faillock.so' "$pam_file"
    fi
done


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_passwords_pam_faillock_fail_interval # promote to variable
  set_fact:
    var_accounts_passwords_pam_faillock_fail_interval: !!str 900
  tags:
    - always

- name: Add auth pam_faillock preauth fail_interval before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: before
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80669-5
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add fail_interval argument to auth pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80669-5
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock aufthfail fail_interval after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: after
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80669-5
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add fail_interval argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80669-5
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80669-5
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Set Lockout Time for Failed Password Attempts   [ref]

To configure the system to lock out accounts after a number of incorrect login attempts and require an administrator to unlock the account using pam_faillock.so, modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • add the following line immediately before the pam_unix.so statement in the AUTH section:
    auth required pam_faillock.so preauth silent deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately after the pam_unix.so statement in the AUTH section:
    auth [default=die] pam_faillock.so authfail deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately before the pam_unix.so statement in the ACCOUNT section:
    account required pam_faillock.so
If unlock_time is set to 0, manual intervention by an administrator is required to unlock a user.

Rationale:

Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks. Ensuring that an administrator is involved in unlocking locked accounts draws appropriate attention to such situations.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_unlock_time
Identifiers and References

Identifiers:  CCE-80670-3

References:  5.3.2, 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(b), PR.AC-7, FMT_MOF_EXT.1, Req-8.1.7, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SRG-OS-000329-VMM-001180




var_accounts_passwords_pam_faillock_unlock_time="0"

AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

for pam_file in "${AUTH_FILES[@]}"
do
    # is auth required pam_faillock.so preauth present?
    if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*'"unlock_time"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock.so.*preauth.*silent.*\)\('"unlock_time"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock.so.*preauth.*silent.*/ s/$/ '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        fi
    # auth required pam_faillock.so preauth is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/i auth        required      pam_faillock.so preauth silent '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time" "$pam_file"
    fi
    # is auth default pam_faillock.so authfail present?
    if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*'"unlock_time"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\('"unlock_time"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*[default=die].*pam_faillock.so.*authfail.*/ s/$/ '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        fi
    # auth default pam_faillock.so authfail is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/a auth        [default=die] pam_faillock.so authfail '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time" "$pam_file"
    fi
    if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
        sed -E -i --follow-symlinks '/^\s*account\s*required\s*pam_unix.so/i account     required      pam_faillock.so' "$pam_file"
    fi
done


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_passwords_pam_faillock_unlock_time # promote to variable
  set_fact:
    var_accounts_passwords_pam_faillock_unlock_time: !!str 0
  tags:
    - always

- name: Add auth pam_faillock preauth unlock_time before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: before
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80670-3
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add unlock_time argument to pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80670-3
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock authfail unlock_interval after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: after
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80670-3
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add unlock_time argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80670-3
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80670-3
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Set Deny For Failed Password Attempts   [ref]

To configure the system to lock out accounts after a number of incorrect login attempts using pam_faillock.so, modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • add the following line immediately before the pam_unix.so statement in the AUTH section:
    auth required pam_faillock.so preauth silent deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately after the pam_unix.so statement in the AUTH section:
    auth [default=die] pam_faillock.so authfail deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately before the pam_unix.so statement in the ACCOUNT section:
    account required pam_faillock.so

Rationale:

Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny
Identifiers and References

Identifiers:  CCE-80667-9

References:  5.3.2, 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FMT_MOF_EXT.1, Req-8.1.6, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SRG-OS-000021-VMM-000050




var_accounts_passwords_pam_faillock_deny="3"

AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

for pam_file in "${AUTH_FILES[@]}"
do
    # is auth required pam_faillock.so preauth present?
    if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*'"deny"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock.so.*preauth.*silent.*\)\('"deny"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock.so.*preauth.*silent.*/ s/$/ '"deny"'='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        fi
    # auth required pam_faillock.so preauth is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/i auth        required      pam_faillock.so preauth silent '"deny"'='"$var_accounts_passwords_pam_faillock_deny" "$pam_file"
    fi
    # is auth default pam_faillock.so authfail present?
    if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*'"deny"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\('"deny"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*[default=die].*pam_faillock.so.*authfail.*/ s/$/ '"deny"'='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        fi
    # auth default pam_faillock.so authfail is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/a auth        [default=die] pam_faillock.so authfail '"deny"'='"$var_accounts_passwords_pam_faillock_deny" "$pam_file"
    fi
    if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
        sed -E -i --follow-symlinks '/^\s*account\s*required\s*pam_unix.so/i account     required      pam_faillock.so' "$pam_file"
    fi
done


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_passwords_pam_faillock_deny # promote to variable
  set_fact:
    var_accounts_passwords_pam_faillock_deny: !!str 3
  tags:
    - always

- name: Add auth pam_faillock preauth deny before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent deny={{ var_accounts_passwords_pam_faillock_deny
      }}
    state: before
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80667-9
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add deny argument to auth pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent deny={{ var_accounts_passwords_pam_faillock_deny
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80667-9
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock authfail deny after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail deny={{ var_accounts_passwords_pam_faillock_deny }}
    state: after
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80667-9
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add deny argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    new_type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail deny={{ var_accounts_passwords_pam_faillock_deny }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80667-9
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  tags:
    - CCE-80667-9
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
Group   Secure Session Configuration Files for Login Accounts   Group contains 1 group and 4 rules

[ref]   When a user logs into a Unix account, the system configures the user's session by reading a number of files. Many of these files are located in the user's home directory, and may have weak permissions as a result of user error or misconfiguration. If an attacker can modify or even read certain types of account configuration information, they can often gain full access to the affected user's account. Therefore, it is important to test and correct configuration file permissions for interactive accounts, particularly those of privileged users such as root or system administrators.

Group   Ensure that Users Have Sensible Umask Values   Group contains 3 rules

[ref]   The umask setting controls the default permissions for the creation of new files. With a default umask setting of 077, files and directories created by users will not be readable by any other user on the system. Users who wish to make specific files group- or world-readable can accomplish this by using the chmod command. Additionally, users can make all their files readable to their group by default by setting a umask of 027 in their shell configuration files. If default per-user groups exist (that is, if every user has a default group whose name is the same as that user's username and whose only member is the user), then it may even be safe for users to select a umask of 007, making it very easy to intentionally share files with groups of which the user is a member.

Rule   Ensure the Default Umask is Set Correctly in /etc/profile   [ref]

To ensure the default umask controlled by /etc/profile is set properly, add or correct the umask setting in /etc/profile to read as follows:

umask 027

Rationale:

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_accounts_umask_etc_profile
Identifiers and References

Identifiers:  CCE-81035-8

References:  NT28(R35), 5.4.4, 18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, AC-6(1), CM-6(a), PR.IP-2, SRG-OS-000480-GPOS-00228




var_accounts_user_umask="027"

grep -q umask /etc/profile && \
  sed -i "s/umask.*/umask $var_accounts_user_umask/g" /etc/profile
if ! [ $? -eq 0 ]; then
    echo "umask $var_accounts_user_umask" >> /etc/profile
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_user_umask # promote to variable
  set_fact:
    var_accounts_user_umask: !!str 027
  tags:
    - always

- name: Set user umask in /etc/profile
  replace:
    path: /etc/profile
    regexp: umask.*
    replace: umask {{ var_accounts_user_umask }}
  tags:
    - CCE-81035-8
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - accounts_umask_etc_profile
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - unknown_severity

Rule   Ensure the Default C Shell Umask is Set Correctly   [ref]

To ensure the default umask for users of the C shell is set properly, add or correct the umask setting in /etc/csh.cshrc to read as follows:

umask 027

Rationale:

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_accounts_umask_etc_csh_cshrc
Identifiers and References

Identifiers:  CCE-81037-4

References:  18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, AC-6(1), CM-6(a), PR.IP-2, SRG-OS-000480-GPOS-00228




var_accounts_user_umask="027"

grep -q umask /etc/csh.cshrc && \
  sed -i "s/umask.*/umask $var_accounts_user_umask/g" /etc/csh.cshrc
if ! [ $? -eq 0 ]; then
    echo "umask $var_accounts_user_umask" >> /etc/csh.cshrc
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_user_umask # promote to variable
  set_fact:
    var_accounts_user_umask: !!str 027
  tags:
    - always

- name: Set user umask in /etc/csh.cshrc
  replace:
    path: /etc/csh.cshrc
    regexp: umask.*
    replace: umask {{ var_accounts_user_umask }}
  tags:
    - CCE-81037-4
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - accounts_umask_etc_csh_cshrc
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - unknown_severity

Rule   Ensure the Default Bash Umask is Set Correctly   [ref]

To ensure the default umask for users of the Bash shell is set properly, add or correct the umask setting in /etc/bashrc to read as follows:

umask 027

Rationale:

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_accounts_umask_etc_bashrc
Identifiers and References

Identifiers:  CCE-81036-6

References:  5.4.4, 18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, AC-6(1), CM-6(a), PR.IP-2, SRG-OS-000480-GPOS-00228




var_accounts_user_umask="027"

grep -q umask /etc/bashrc && \
  sed -i "s/umask.*/umask $var_accounts_user_umask/g" /etc/bashrc
if ! [ $? -eq 0 ]; then
    echo "umask $var_accounts_user_umask" >> /etc/bashrc
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_user_umask # promote to variable
  set_fact:
    var_accounts_user_umask: !!str 027
  tags:
    - always

- name: Set user umask in /etc/bashrc
  replace:
    path: /etc/bashrc
    regexp: umask.*
    replace: umask {{ var_accounts_user_umask }}
  tags:
    - CCE-81036-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - accounts_umask_etc_bashrc
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - unknown_severity
Group   Protect Accounts by Restricting Password-Based Login   Group contains 3 groups and 3 rules

[ref]   Conventionally, Unix shell accounts are accessed by providing a username and password to a login program, which tests these values for correctness using the /etc/passwd and /etc/shadow files. Password-based login is vulnerable to guessing of weak passwords, and to sniffing and man-in-the-middle attacks against passwords entered over a network or at an insecure console. Therefore, mechanisms for accessing accounts by entering usernames and passwords should be restricted to those which are operationally necessary.

Group   Verify Proper Storage and Existence of Password Hashes   Group contains 1 rule

[ref]   By default, password hashes for local accounts are stored in the second field (colon-separated) in /etc/shadow. This file should be readable only by processes running with root credentials, preventing users from casually accessing others' password hashes and attempting to crack them. However, it remains possible to misconfigure the system and store password hashes in world-readable files such as /etc/passwd, or to even store passwords themselves in plaintext on the system. Using system-provided tools for password change/creation should allow administrators to avoid such misconfiguration.

Rule   Prevent Login to Accounts With Empty Password   [ref]

If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the nullok option in /etc/pam.d/system-auth to prevent logins with empty passwords.

Rationale:

If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_no_empty_passwords
Identifiers and References

Identifiers:  CCE-80841-0

References:  1, 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, CCI-000366, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(1)(a), IA-5(c), CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, FIA_AFL.1, Req-8.2.3, SRG-OS-000480-GPOS-00227



sed --follow-symlinks -i 's/\<nullok\>//g' /etc/pam.d/system-auth
sed --follow-symlinks -i 's/\<nullok\>//g' /etc/pam.d/password-auth


Complexity:low
Disruption:medium
Strategy:configure
- name: Prevent Log In to Accounts With Empty Password - system-auth
  replace:
    dest: /etc/pam.d/system-auth
    follow: true
    regexp: nullok
  tags:
    - CCE-80841-0
    - CJIS-5.5.2
    - NIST-800-171-3.1.1
    - NIST-800-171-3.1.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(c)
    - PCI-DSS-Req-8.2.3
    - configure_strategy
    - high_severity
    - low_complexity
    - medium_disruption
    - no_empty_passwords
    - no_reboot_needed

- name: Prevent Log In to Accounts With Empty Password - password-auth
  replace:
    dest: /etc/pam.d/password-auth
    follow: true
    regexp: nullok
  tags:
    - CCE-80841-0
    - CJIS-5.5.2
    - NIST-800-171-3.1.1
    - NIST-800-171-3.1.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(1)(a)
    - NIST-800-53-IA-5(c)
    - PCI-DSS-Req-8.2.3
    - configure_strategy
    - high_severity
    - low_complexity
    - medium_disruption
    - no_empty_passwords
    - no_reboot_needed


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%20Generated%20by%20authselect%20on%20Sat%20Oct%2027%2014%3A59%3A36%202018%0A%23%20Do%20not%20modify%20this%20file%20manually.%0A%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_env.so%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_faildelay.so%20delay%3D2000000%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_fprintd.so%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20try_first_pass%0Aauth%20%20%20%20%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet_success%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20forward_pass%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3C%201000%20quiet%0Aaccount%20%20%20%20%20%5Bdefault%3Dbad%20success%3Dok%20user_unknown%3Dignore%5D%20pam_sss.so%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_permit.so%0A%0Apassword%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_pwquality.so%20try_first_pass%20local_users_only%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20sha512%20shadow%20try_first_pass%20use_authtok%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20use_authtok%0Apassword%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_keyinit.so%20revoke%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_limits.so%0A-session%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_systemd.so%0Asession%20%20%20%20%20%5Bsuccess%3D1%20default%3Dignore%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20service%20in%20crond%20quiet%20use_uid%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%0A
        filesystem: root
        mode: 0644
        path: /etc/pam.d/password-auth
      - contents:
          source: data:,%23%20Generated%20by%20authselect%20on%20Sat%20Oct%2027%2014%3A59%3A36%202018%0A%23%20Do%20not%20modify%20this%20file%20manually.%0A%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_env.so%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_faildelay.so%20delay%3D2000000%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_fprintd.so%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20try_first_pass%0Aauth%20%20%20%20%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet_success%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20forward_pass%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3C%201000%20quiet%0Aaccount%20%20%20%20%20%5Bdefault%3Dbad%20success%3Dok%20user_unknown%3Dignore%5D%20pam_sss.so%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_permit.so%0A%0Apassword%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_pwquality.so%20try_first_pass%20local_users_only%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20sha512%20shadow%20try_first_pass%20use_authtok%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20use_authtok%0Apassword%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_keyinit.so%20revoke%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_limits.so%0A-session%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_systemd.so%0Asession%20%20%20%20%20%5Bsuccess%3D1%20default%3Dignore%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20service%20in%20crond%20quiet%20use_uid%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%0A
        filesystem: root
        mode: 0644
        path: /etc/pam.d/system-auth
Group   Restrict Root Logins   Group contains 1 rule

[ref]   Direct root logins should be allowed only for emergency use. In normal situations, the administrator should access the system via a unique unprivileged account, and then use su or sudo to execute privileged commands. Discouraging administrators from accessing the root account directly ensures an audit trail in organizations with multiple administrators. Locking down the channels through which root can connect directly also reduces opportunities for password-guessing against the root account. The login program uses the file /etc/securetty to determine which interfaces should allow root logins. The virtual devices /dev/console and /dev/tty* represent the system consoles (accessible via the Ctrl-Alt-F1 through Ctrl-Alt-F6 keyboard sequences on a default installation). The default securetty file also contains /dev/vc/*. These are likely to be deprecated in most environments, but may be retained for compatibility. Root should also be prohibited from connecting via network protocols. Other sections of this document include guidance describing how to prevent root from logging in via SSH.

Group   Set Password Expiration Parameters   Group contains 1 rule

[ref]   The file /etc/login.defs controls several password-related settings. Programs such as passwd, su, and login consult /etc/login.defs to determine behavior with regard to password aging, expiration warnings, and length. See the man page login.defs(5) for more information.

Users should be forced to change their passwords, in order to decrease the utility of compromised passwords. However, the need to change passwords often should be balanced against the risk that users will reuse or write down passwords if forced to change them too often. Forcing password changes every 90-360 days, depending on the environment, is recommended. Set the appropriate value as PASS_MAX_DAYS and apply it to existing accounts with the -M flag.

The PASS_MIN_DAYS (-m) setting prevents password changes for 7 days after the first change, to discourage password cycling. If you use this setting, train users to contact an administrator for an emergency password change in case a new password becomes compromised. The PASS_WARN_AGE (-W) setting gives users 7 days of warnings at login time that their passwords are about to expire.

For example, for each existing human user USER, expiration parameters could be adjusted to a 180 day maximum password age, 7 day minimum password age, and 7 day warning period with the following command:

$ sudo chage -M 180 -m 7 -W 7 USER

Group   Protect Physical Console Access   Group contains 2 groups and 10 rules

[ref]   It is impossible to fully protect a system from an attacker with physical access, so securing the space in which the system is located should be considered a necessary step. However, there are some steps which, if taken, make it more difficult for an attacker to quickly or undetectably modify a system from its console.

Group   Configure Screen Locking   Group contains 1 group and 5 rules

[ref]   When a user must temporarily leave an account logged-in, screen locking should be employed to prevent passersby from abusing the account. User education and training is particularly important for screen locking to be effective, and policies can be implemented to reinforce this.

Automatic screen locking is only meant as a safeguard for those cases where a user forgot to lock the screen.

Group   Configure Console Screen Locking   Group contains 5 rules

[ref]   A console screen locking mechanism is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operation system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock.

Rule   Install the tmux Package   [ref]

To enable console screen locking, install the tmux package. The tmux package can be installed with the following command:

$ sudo yum install tmux
Instruct users to begin new terminal sessions with the following command:
$ tmux
The console can now be locked with the following key combination:
ctrl+b :lock-session

Rationale:

A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operation system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock.

The tmux package allows for a session lock to be implemented and configured.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_tmux_installed
Identifiers and References

Identifiers:  CCE-80644-8

References:  1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.10, CCI-000058, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000030-GPOS-00011, SRG-OS-000030-VMM-000110



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "tmux" ; then
    yum install -y "tmux"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure tmux is installed
  package:
    name: tmux
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80644-8
    - NIST-800-171-3.1.10
    - NIST-800-53-CM-6(a)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_tmux_installed


Complexity:low
Disruption:low
Strategy:enable
include install_tmux

class install_tmux {
  package { 'tmux':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=tmux

Rule   Prevent user from disabling the screen lock   [ref]

The tmux terminal multiplexer is used to implement autimatic session locking. It should not be listed in /etc/shells.

Rationale:

Not listing tmux among permitted shells prevents malicious program running as user from lowering security by disabling the screen lock.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_tmux_in_shells
Identifiers and References

Identifiers:  CCE-82361-7

References:  FMT_SMF_EXT.1, SRG-OS-000324-GPOS-00125




if grep -q 'tmux$' /etc/shells ; then
	sed -i '/tmux$/d' /etc/shells
fi


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,/bin/sh%0A/bin/bash%0A/usr/bin/sh%0A/usr/bin/bash%0A
        filesystem: root
        mode: 0644
        path: /etc/shells

Rule   Configure tmux to lock session after inactivity   [ref]

To enable console screen locking in tmux terminal multiplexer after a period of inactivity, the lock-after-time option has to be set to nonzero value in /etc/tmux.conf.

Rationale:

Locking the session after a period of inactivity limits the potential exposure if the session is left unattended.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_tmux_lock_after_time
Identifiers and References

Identifiers:  CCE-82199-1

References:  FMT_SMF_EXT.1, SRG-OS-000029-GPOS-00010




tmux_conf="/etc/tmux.conf"

if grep -qP '^\s*set\s+-g\s+lock-after-time' "$tmux_conf" ; then
    sed -i 's/^\s*set\s\+-g\s\+lock-after-time.*$/set -g lock-after-time 900/' "$tmux_conf"
else
    echo "set -g lock-after-time 900" >> "$tmux_conf"
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: Configure tmux to lock session after inactivity
  block:

    - name: Deduplicate values from /etc/tmux.conf
      lineinfile:
        path: /etc/tmux.conf
        create: false
        regexp: ^\s*set -g lock-after-time\s+
        state: absent

    - name: Insert correct line to /etc/tmux.conf
      lineinfile:
        path: /etc/tmux.conf
        create: true
        line: set -g lock-after-time 900
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82199-1
    - configure_tmux_lock_after_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure the tmux Lock Command   [ref]

To enable console screen locking in tmux terminal multiplexer, the vlock command must be configured to be used as a locking mechanism. Add the following line to /etc/tmux.conf:

set -g lock-command vlock
. The console can now be locked with the following key combination:
ctrl+b :lock-session

Rationale:

The tmux package allows for a session lock to be implemented and configured. However, the session lock is implemented by an external command. The tmux default configuration does not contain an effective session lock.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_tmux_lock_command
Identifiers and References

Identifiers:  CCE-80940-0

References:  CCI-000056, CCI-000058, AC-11(a), AC-11(b), CM-6(a), SRG-OS-000028-GPOS-00009, SRG-OS-000028-VMM-000090, SRG-OS-000030-VMM-000110




tmux_conf="/etc/tmux.conf"

if grep -qP '^\s*set\s+-g\s+lock-command' "$tmux_conf" ; then
    sed -i 's/^\s*set\s\+-g\s\+lock-command.*$/set -g lock-command vlock/' "$tmux_conf"
else
    echo "set -g lock-command vlock" >> "$tmux_conf"
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: Configure the tmux Lock Command
  block:

    - name: Deduplicate values from /etc/tmux.conf
      lineinfile:
        path: /etc/tmux.conf
        create: false
        regexp: ^\s*set -g lock-command\s+
        state: absent

    - name: Insert correct line to /etc/tmux.conf
      lineinfile:
        path: /etc/tmux.conf
        create: true
        line: set -g lock-command vlock
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80940-0
    - NIST-800-53-AC-11(a)
    - NIST-800-53-AC-11(b)
    - NIST-800-53-CM-6(a)
    - configure_tmux_lock_command
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Support session locking with tmux   [ref]

The tmux terminal multiplexer is used to implement automatic session locking. It should be started from /etc/bashrc.

Rationale:

Unlike bash itself, the tmux terminal multiplexer provides a mechanism to lock sessions after period of inactivity.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_bashrc_exec_tmux
Identifiers and References

Identifiers:  CCE-82266-8

References:  FMT_SMF_EXT.1, SRG-OS-000031-GPOS-00012




if ! grep -x '  case "$name" in sshd|login) exec tmux ;; esac' /etc/bashrc; then
    cat >> /etc/bashrc <<'EOF'
if [ "$PS1" ]; then
  parent=$(ps -o ppid= -p $$)
  name=$(ps -o comm= -p $parent)
  case "$name" in sshd|login) exec tmux ;; esac
fi
EOF
fi

Rule   Disable debug-shell SystemD Service   [ref]

SystemD's debug-shell service is intended to diagnose SystemD related boot issues with various systemctl commands. Once enabled and following a system reboot, the root shell will be available on tty9 which is access by pressing CTRL-ALT-F9. The debug-shell service should only be used for SystemD related issues and should otherwise be disabled.

By default, the debug-shell SystemD service is already disabled. The debug-shell service can be disabled with the following command:

$ sudo systemctl disable debug-shell.service
The debug-shell service can be masked with the following command:
$ sudo systemctl mask debug-shell.service

Rationale:

This prevents attackers with physical access from trivially bypassing security on the machine through valid troubleshooting configurations and gaining root access when the system is rebooted.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_debug-shell_disabled
Identifiers and References

Identifiers:  CCE-80876-6

References:  3.4.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), FIA_AFL.1, SRG-OS-000324-GPOS-00125



Complexity:low
Disruption:low
Strategy:disable


SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" stop 'debug-shell.service'
"$SYSTEMCTL_EXEC" disable 'debug-shell.service'
"$SYSTEMCTL_EXEC" mask 'debug-shell.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" list-unit-files | grep -q '^debug-shell.socket'; then
    "$SYSTEMCTL_EXEC" stop 'debug-shell.socket'
    "$SYSTEMCTL_EXEC" disable 'debug-shell.socket'
    "$SYSTEMCTL_EXEC" mask 'debug-shell.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'debug-shell.service' || true


Complexity:low
Disruption:low
Strategy:disable
- name: Disable service debug-shell
  block:

    - name: Gather the service facts
      service_facts: null

    - name: Disable service debug-shell
      systemd:
        name: debug-shell.service
        enabled: 'no'
        state: stopped
        masked: 'yes'
      when: '"debug-shell.service" in ansible_facts.services'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80876-6
    - NIST-800-171-3.4.5
    - disable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_debug-shell_disabled

- name: Unit Socket Exists - debug-shell.socket
  command: systemctl list-unit-files debug-shell.socket
  args:
    warn: false
  register: socket_file_exists
  changed_when: false
  ignore_errors: true
  check_mode: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80876-6
    - NIST-800-171-3.4.5
    - disable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_debug-shell_disabled

- name: Disable socket debug-shell
  systemd:
    name: debug-shell.socket
    enabled: 'no'
    state: stopped
    masked: 'yes'
  when:
    - '"debug-shell.socket" in socket_file_exists.stdout_lines[1]'
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80876-6
    - NIST-800-171-3.4.5
    - disable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_debug-shell_disabled


Complexity:low
Disruption:low
Strategy:enable
include disable_debug-shell

class disable_debug-shell {
  service {'debug-shell':
    enable => false,
    ensure => 'stopped',
  }
}


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    systemd:
      units:
      - name: debug-shell.service
        enabled: false
        mask: true
      - name: debug-shell.socket
        enabled: false
        mask: true


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    systemd:
      units:
      - enabled: false
        name: debug-shell.service

Rule   Disable Ctrl-Alt-Del Burst Action   [ref]

By default, SystemD will reboot the system if the Ctrl-Alt-Del key sequence is pressed Ctrl-Alt-Delete more than 7 times in 2 seconds.

To configure the system to ignore the CtrlAltDelBurstAction setting, add or modify the following to /etc/systemd/system.conf:

CtrlAltDelBurstAction=none

Warning:  Disabling the Ctrl-Alt-Del key sequence in /etc/init/control-alt-delete.conf DOES NOT disable the Ctrl-Alt-Del key sequence if running in runlevel 6 (e.g. in GNOME, KDE, etc.)! The Ctrl-Alt-Del key sequence will only be disabled if running in the non-graphical runlevel 3.
Rationale:

A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_disable_ctrlaltdel_burstaction
Identifiers and References

Identifiers:  CCE-80784-2

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000366, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), CM-6(a), PR.AC-4, PR.DS-5, SRG-OS-000324-GPOS-00125



# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/systemd/system.conf' '^CtrlAltDelBurstAction=' 'none' 'CCE-80784-2' '%s=%s'


Complexity:low
Disruption:low
Strategy:disable
- name: Disable Ctrl-Alt-Del Burst Action
  lineinfile:
    dest: /etc/systemd/system.conf
    state: present
    regexp: ^CtrlAltDelBurstAction
    line: CtrlAltDelBurstAction=none
    create: true
  tags:
    - CCE-80784-2
    - NIST-800-171-3.4.5
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-6(a)
    - disable_ctrlaltdel_burstaction
    - disable_strategy
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,CtrlAltDelBurstAction%3Dnone
        filesystem: root
        mode: 0644
        path: /etc/systemd/system.conf.d/disable_ctrlaltdelete_burstaction.conf

Rule   Require Authentication for Single User Mode   [ref]

Single-user mode is intended as a system recovery method, providing a single user root access to the system by providing a boot option at startup. By default, no authentication is performed if single-user mode is selected.

By default, single-user mode is protected by requiring a password and is set in /usr/lib/systemd/system/rescue.service.

Rationale:

This prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_require_singleuser_auth
Identifiers and References

Identifiers:  CCE-80855-0

References:  1.5.3, 1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.1.1, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-2, AC-3, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_AFL.1, SRG-OS-000080-GPOS-00048




service_file="/usr/lib/systemd/system/rescue.service"

sulogin="/usr/lib/systemd/systemd-sulogin-shell rescue"

if grep "^ExecStart=.*" "$service_file" ; then
    sed -i "s%^ExecStart=.*%ExecStart=-$sulogin%" "$service_file"
else
    echo "ExecStart=-$sulogin" >> "$service_file"
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: require single user mode password
  lineinfile:
    create: true
    dest: /usr/lib/systemd/system/rescue.service
    regexp: ^#?ExecStart=
    line: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80855-0
    - NIST-800-171-3.1.1
    - NIST-800-171-3.4.5
    - NIST-800-53-AC-3
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - require_singleuser_auth
    - restrict_strategy

Rule   Disable Ctrl-Alt-Del Reboot Activation   [ref]

By default, SystemD will reboot the system if the Ctrl-Alt-Del key sequence is pressed.

To configure the system to ignore the Ctrl-Alt-Del key sequence from the command line instead of rebooting the system, do either of the following:

ln -sf /dev/null /etc/systemd/system/ctrl-alt-del.target
or
systemctl mask ctrl-alt-del.target


Do not simply delete the /usr/lib/systemd/system/ctrl-alt-del.service file, as this file may be restored during future system updates.

Warning:  Disabling the Ctrl-Alt-Del key sequence in /etc/init/control-alt-delete.conf DOES NOT disable the Ctrl-Alt-Del key sequence if running in runlevel 6 (e.g. in GNOME, KDE, etc.)! The Ctrl-Alt-Del key sequence will only be disabled if running in the non-graphical runlevel 3.
Rationale:

A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_disable_ctrlaltdel_reboot
Identifiers and References

Identifiers:  CCE-80785-9

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000366, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000324-GPOS-00125, SRG-OS-000480-GPOS-00227



# The process to disable ctrl+alt+del has changed in RHEL7. 
# Reference: https://access.redhat.com/solutions/1123873

systemctl mask ctrl-alt-del.target


Complexity:low
Disruption:low
Strategy:disable
- name: Disable Ctrl-Alt-Del Reboot Activation
  systemd:
    name: ctrl-alt-del.target
    masked: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80785-9
    - NIST-800-171-3.4.5
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - disable_ctrlaltdel_reboot
    - disable_strategy
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed

Rule   Verify that Interactive Boot is Disabled   [ref]

Red Hat Enterprise Linux 8 systems support an "interactive boot" option that can be used to prevent services from being started. On a Red Hat Enterprise Linux 8 system, interactive boot can be enabled by providing a 1, yes, true, or on value to the systemd.confirm_spawn kernel argument in /etc/default/grub. Remove any instance of

systemd.confirm_spawn=(1|yes|true|on)
from the kernel arguments in that file to disable interactive boot. It is also required to change the runtime configuration, run:
/sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"

Rationale:

Using interactive boot, the console user could disable auditing, firewalls, or other services, weakening system security.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_disable_interactive_boot
Identifiers and References

Identifiers:  CCE-80826-1

References:  11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.2, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, SC-2(1), CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_AFL.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Reboot:true
Strategy:restrict

CONFIRM_SPAWN_YES="systemd.confirm_spawn=\(1\|yes\|true\|on\)"
CONFIRM_SPAWN_NO="systemd.confirm_spawn=no"

if grep -q "\(GRUB_CMDLINE_LINUX\|GRUB_CMDLINE_LINUX_DEFAULT\)" /etc/default/grub
then
	sed -i "s/${CONFIRM_SPAWN_YES}/${CONFIRM_SPAWN_NO}/" /etc/default/grub
fi
# Remove 'systemd.confirm_spawn' kernel argument also from runtime settings
/sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Verify that Interactive Boot is Disabled in /etc/default/grub
  replace:
    dest: /etc/default/grub
    regexp: systemd.confirm_spawn=(1|yes|true|on)
    replace: systemd.confirm_spawn=no
  tags:
    - CCE-80826-1
    - NIST-800-171-3.1.2
    - NIST-800-171-3.4.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-2(1)
    - grub2_disable_interactive_boot
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Verify that Interactive Boot is Disabled (runtime)
  command: /sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"
  tags:
    - CCE-80826-1
    - NIST-800-171-3.1.2
    - NIST-800-171-3.4.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-2(1)
    - grub2_disable_interactive_boot
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy
Group   System Accounting with auditd   Group contains 2 groups and 26 rules

[ref]   The audit service provides substantial capabilities for recording system activities. By default, the service audits about SELinux AVC denials and certain types of security-relevant events such as system logins, account modifications, and authentication events performed by programs such as sudo. Under its default configuration, auditd has modest disk space requirements, and should not noticeably impact system performance.

NOTE: The Linux Audit daemon auditd can be configured to use the augenrules program to read audit rules files (*.rules) located in /etc/audit/rules.d location and compile them to create the resulting form of the /etc/audit/audit.rules configuration file during the daemon startup (default configuration). Alternatively, the auditd daemon can use the auditctl utility to read audit rules from the /etc/audit/audit.rules configuration file during daemon startup, and load them into the kernel. The expected behavior is configured via the appropriate ExecStartPost directive setting in the /usr/lib/systemd/system/auditd.service configuration file. To instruct the auditd daemon to use the augenrules program to read audit rules (default configuration), use the following setting:

ExecStartPost=-/sbin/augenrules --load
in the /usr/lib/systemd/system/auditd.service configuration file. In order to instruct the auditd daemon to use the auditctl utility to read audit rules, use the following setting:
ExecStartPost=-/sbin/auditctl -R /etc/audit/audit.rules
in the /usr/lib/systemd/system/auditd.service configuration file. Refer to [Service] section of the /usr/lib/systemd/system/auditd.service configuration file for further details.

Government networks often have substantial auditing requirements and auditd can be configured to meet these requirements. Examining some example audit records demonstrates how the Linux audit system satisfies common requirements. The following example from Fedora Documentation available at https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/SELinux_Users_and_Administrators_Guide/sect-Security-Enhanced_Linux-Troubleshooting-Fixing_Problems.html#sect-Security-Enhanced_Linux-Fixing_Problems-Raw_Audit_Messages shows the substantial amount of information captured in a two typical "raw" audit messages, followed by a breakdown of the most important fields. In this example the message is SELinux-related and reports an AVC denial (and the associated system call) that occurred when the Apache HTTP Server attempted to access the /var/www/html/file1 file (labeled with the samba_share_t type):
type=AVC msg=audit(1226874073.147:96): avc:  denied  { getattr } for pid=2465 comm="httpd"
path="/var/www/html/file1" dev=dm-0 ino=284133 scontext=unconfined_u:system_r:httpd_t:s0
tcontext=unconfined_u:object_r:samba_share_t:s0 tclass=file

type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)
  • msg=audit(1226874073.147:96)
    • The number in parentheses is the unformatted time stamp (Epoch time) for the event, which can be converted to standard time by using the date command.
  • { getattr }
    • The item in braces indicates the permission that was denied. getattr indicates the source process was trying to read the target file's status information. This occurs before reading files. This action is denied due to the file being accessed having the wrong label. Commonly seen permissions include getattr, read, and write.
  • comm="httpd"
    • The executable that launched the process. The full path of the executable is found in the exe= section of the system call (SYSCALL) message, which in this case, is exe="/usr/sbin/httpd".
  • path="/var/www/html/file1"
    • The path to the object (target) the process attempted to access.
  • scontext="unconfined_u:system_r:httpd_t:s0"
    • The SELinux context of the process that attempted the denied action. In this case, it is the SELinux context of the Apache HTTP Server, which is running in the httpd_t domain.
  • tcontext="unconfined_u:object_r:samba_share_t:s0"
    • The SELinux context of the object (target) the process attempted to access. In this case, it is the SELinux context of file1. Note: the samba_share_t type is not accessible to processes running in the httpd_t domain.
  • From the system call (SYSCALL) message, two items are of interest:
    • success=no: indicates whether the denial (AVC) was enforced or not. success=no indicates the system call was not successful (SELinux denied access). success=yes indicates the system call was successful - this can be seen for permissive domains or unconfined domains, such as initrc_t and kernel_t.
    • exe="/usr/sbin/httpd": the full path to the executable that launched the process, which in this case, is exe="/usr/sbin/httpd".

Group   System Accounting with auditd   Group contains 16 rules

[ref]   The auditd program can perform comprehensive monitoring of system activity. This section makes use of recommended configuration settings for specific policies or use cases. The rules in this section make use of rules defined in /usr/share/doc/audit-VERSION/rules.

Rule   Configure auditing of successful ownership changes   [ref]

Ensure that successful attempts to change an ownership of files or directories are audited. The following rules configure audit as described above:

## Successful ownership change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-owner-change
-a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-owner-change
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-6-owner-change-success.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-6-owner-change-success.rules /etc/audit/rules.d/
The file has the following SHA-256 checksum:
7eb41a6aaf6737c2571b6424fae7fa53af4b41a9115b6c5732a5778ccd9900ad
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Auditing of successful ownership changes of files or directories helps in monitoring or investingating of activities performed on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_owner_change_success
Identifiers and References

Identifiers:  CCE-82385-6

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-6-owner-change-success.rules
## Successful ownership change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-owner-change
-a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-owner-change
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-6-owner-change-success.rules
    according to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-6-owner-change-success.rules
    content: |
      ## Successful ownership change
      -a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-owner-change
      -a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-owner-change
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82385-6
    - NIST-800-53-AU-2(a)
    - audit_owner_change_success
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure auditing of successful file modifications   [ref]

Ensure that successful attempts to modify a file are audited. The following rules configure audit as described above:

## Successful file modifications (open for write or truncate)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b32 -S open -F a1&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b64 -S open -F a1&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b32 -S truncate,ftruncate -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b64 -S truncate,ftruncate -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-2-modify-success.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-2-modify-success.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Auditing of successful attempts to modify a file helps in investigation of actions which happened on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_modify_success
Identifiers and References

Identifiers:  CCE-82832-7

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-2-modify-success.rules
## Successful file modifications (open for write or truncate)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b32 -S open -F a1&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b64 -S open -F a1&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b32 -S truncate,ftruncate -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
-a always,exit -F arch=b64 -S truncate,ftruncate -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-2-modify-success.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-2-modify-success.rules
    content: |
      ## Successful file modifications (open for write or truncate)
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
      -a always,exit -F arch=b32 -S open -F a1&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
      -a always,exit -F arch=b64 -S open -F a1&01003 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
      -a always,exit -F arch=b32 -S truncate,ftruncate -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
      -a always,exit -F arch=b64 -S truncate,ftruncate -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-modification
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82832-7
    - NIST-800-53-AU-2(a)
    - audit_modify_success
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Successful%20file%20modifications%20%28open%20for%20write%20or%20truncate%29%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%26amp%3B01003%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%26amp%3B01003%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%26amp%3B01003%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%26amp%3B01003%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20truncate%2Cftruncate%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20truncate%2Cftruncate%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-modification%0A
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-2-modify-success.rules

Rule   Configure basic parameters of Audit system   [ref]

Perform basic configuration of Audit system. Make sure that any previously defined rules are cleared, the auditing system is configured to handle sudden bursts of events, and in cases of failure, messages are configured to be directed to system log. The following rules configure audit as described above:

## First rule - delete all
-D

## Increase the buffers to survive stress events.
## Make this bigger for busy systems
-b 8192

## This determine how long to wait in burst of events
--backlog_wait_time 60000

## Set failure mode to syslog
-f 1

The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/10-base-config.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/10-base-config.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load

Rationale:

Without basic configurations, audit may not perform as expected. It may not be able to correctly handle events under stressful conditions, or log events in case of failure.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_basic_configuration
Identifiers and References

Identifiers:  CCE-82827-7

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000365-GPOS-00152, SRG-OS-000475-GPOS-00220



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/10-base-config.rules
## First rule - delete all
-D

## Increase the buffers to survive stress events.
## Make this bigger for busy systems
-b 8192

## This determine how long to wait in burst of events
--backlog_wait_time 60000

## Set failure mode to syslog
-f 1
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/10-base-config.rules according to policy
  copy:
    dest: /etc/audit/rules.d/10-base-config.rules
    content: |
      ## First rule - delete all
      -D

      ## Increase the buffers to survive stress events.
      ## Make this bigger for busy systems
      -b 8192

      ## This determine how long to wait in burst of events
      --backlog_wait_time 60000

      ## Set failure mode to syslog
      -f 1
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82827-7
    - NIST-800-53-AU-2(a)
    - audit_basic_configuration
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20First%20rule%20-%20delete%20all%0A-D%0A%0A%23%23%20Increase%20the%20buffers%20to%20survive%20stress%20events.%0A%23%23%20Make%20this%20bigger%20for%20busy%20systems%0A-b%208192%0A%0A%23%23%20This%20determine%20how%20long%20to%20wait%20in%20burst%20of%20events%0A--backlog_wait_time%2060000%0A%0A%23%23%20Set%20failure%20mode%20to%20syslog%0A-f%201%0A
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/10-base-config.rules

Rule   Configure auditing of successful permission changes   [ref]

Ensure that successful attempts to modify permissions of iles or directories are audited. The following rules configure audit as described above:

## Successful permission change
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-5-perm-change-success.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-5-perm-change-success.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Auditing successful file or directory permission changes helps in monitoring and investigating of activities performed on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_perm_change_success
Identifiers and References

Identifiers:  CCE-82383-1

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-5-perm-change-success.rules
## Successful permission change
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-5-perm-change-success.rules
    according to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-5-perm-change-success.rules
    content: |
      ## Successful permission change
      -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
      -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82383-1
    - NIST-800-53-AU-2(a)
    - audit_perm_change_success
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure auditing of unsuccessful file accesses   [ref]

Ensure that unsuccessful attempts to access a file are audited. The following rules configure audit as described above:

## Unsuccessful file access (any other opens) This has to go last.
-a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
-a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
-a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
-a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Unsuccessful attempts to access a file might be signs of malicious activity happening within the system. Auditing of such activities helps in their monitoring and investigation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_access_failed
Identifiers and References

Identifiers:  CCE-82833-5

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-3-access-failed.rules
## Unsuccessful file access (any other opens) This has to go last.
-a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
-a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
-a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
-a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-3-access-failed.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-3-access-failed.rules
    content: |
      ## Unsuccessful file access (any other opens) This has to go last.
      -a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
      -a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
      -a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
      -a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-access
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82833-5
    - NIST-800-53-AU-2(a)
    - audit_access_failed
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Unsuccessful%20file%20access%20%28any%20other%20opens%29%20This%20has%20to%20go%20last.%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%2Copenat%2Copen_by_handle_at%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-access%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%2Copenat%2Copen_by_handle_at%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-access%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%2Copenat%2Copen_by_handle_at%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-access%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%2Copenat%2Copen_by_handle_at%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-access
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-3-access-failed.rules

Rule   Configure auditing of unsuccessful file modifications   [ref]

Ensure that unsuccessful attempts to modify a file are audited. The following rules configure audit as described above:

## Unsuccessful file modifications (open for write or truncate)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-2-modify-failed.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-2-modify-failed.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Unsuccessful file modifications might be a sign of a malicious action being performed on the system. Auditing of such events helps in detection and investigation of such actions.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_modify_failed
Identifiers and References

Identifiers:  CCE-82830-1

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-2-modify-failed.rules
## Unsuccessful file modifications (open for write or truncate)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b32 -S truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
-a always,exit -F arch=b64 -S truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-2-modify-failed.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-2-modify-failed.rules
    content: |
      ## Unsuccessful file modifications (open for write or truncate)
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b32 -S truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b64 -S truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b32 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b64 -S open -F a1&01003 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b32 -S truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
      -a always,exit -F arch=b64 -S truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-modification
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82830-1
    - NIST-800-53-AU-2(a)
    - audit_modify_failed
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Unsuccessful%20file%20modifications%20%28open%20for%20write%20or%20truncate%29%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2601003%20-F%20exit%3D-EACCES%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2601003%20-F%20exit%3D-EACCES%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%2601003%20-F%20exit%3D-EACCES%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%2601003%20-F%20exit%3D-EACCES%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20truncate%2Cftruncate%20-F%20exit%3D-EACCES%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20truncate%2Cftruncate%20-F%20exit%3D-EACCES%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2601003%20-F%20exit%3D-EPERM%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2601003%20-F%20exit%3D-EPERM%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%2601003%20-F%20exit%3D-EPERM%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%2601003%20-F%20exit%3D-EPERM%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20truncate%2Cftruncate%20-F%20exit%3D-EPERM%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20truncate%2Cftruncate%20-F%20exit%3D-EPERM%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-modification%0A
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-2-modify-failed.rules 

Rule   Configure auditing of unsuccessful file deletions   [ref]

Ensure that unsuccessful attempts to delete a file are audited. The following rules configure audit as described above:

## Unsuccessful file delete
-a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-4-delete-failed.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-4-delete-failed.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Unsuccessful attempts to delete a file might be signs of malicious activities. Auditing of such events help in monitoring and investigating of such activities.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_delete_failed
Identifiers and References

Identifiers:  CCE-82835-0

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205, SRG-OS-000468-GPOS-00212, SRG-OS-000467-GPOS-00211



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-4-delete-failed.rules
## Unsuccessful file delete
-a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-4-delete-failed.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-4-delete-failed.rules
    content: |
      ## Unsuccessful file delete
      -a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
      -a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
      -a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
      -a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82835-0
    - NIST-800-53-AU-2(a)
    - audit_delete_failed
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Unsuccessful%20file%20delete%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20unlink%2Cunlinkat%2Crename%2Crenameat%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-delete%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20unlink%2Cunlinkat%2Crename%2Crenameat%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-delete%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20unlink%2Cunlinkat%2Crename%2Crenameat%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-delete%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20unlink%2Cunlinkat%2Crename%2Crenameat%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-delete
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-4-delete-failed.rules

Rule   Configure auditing of unsuccessful permission changes   [ref]

Ensure that unsuccessful attempts to change file or directory permissions are audited. The following rules configure audit as described above:

## Unsuccessful permission change
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-5-perm-change-failed.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-5-perm-change-failed.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Unsuccessful attempts to change permissions of files or directories might be signs of malicious activity. Having such events audited helps in monitoring and investigation of such activities.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_perm_change_failed
Identifiers and References

Identifiers:  CCE-82837-6

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-5-perm-change-failed.rules
## Unsuccessful permission change
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-5-perm-change-failed.rules
    according to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-5-perm-change-failed.rules
    content: |
      ## Unsuccessful permission change
      -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
      -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
      -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
      -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat,setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-perm-change
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82837-6
    - NIST-800-53-AU-2(a)
    - audit_perm_change_failed
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure auditing of loading and unloading of kernel modules   [ref]

Ensure that loading and unloading of kernel modules is audited. The following rules configure audit as described above:

## These rules watch for kernel module insertion. By monitoring
## the syscall, we do not need any watches on programs.
-a always,exit -F arch=b32 -S init_module,finit_module -F key=module-load
-a always,exit -F arch=b64 -S init_module,finit_module -F key=module-load
-a always,exit -F arch=b32 -S delete_module -F key=module-unload
-a always,exit -F arch=b64 -S delete_module -F key=module-unload
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/43-module-load.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/43-module-load.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load

Rationale:

Loading of a malicious kernel module introduces a risk to the system, as the module has access to sensitive data and perform actions at the operating system kernel level. Having such events audited helps in monitoring and investigating of malicious activities.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_module_load
Identifiers and References

Identifiers:  CCE-82838-4

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222, SRG-OS-000475-GPOS-00220



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/43-module-load.rules
## These rules watch for kernel module insertion. By monitoring
## the syscall, we do not need any watches on programs.
-a always,exit -F arch=b32 -S init_module,finit_module -F key=module-load
-a always,exit -F arch=b64 -S init_module,finit_module -F key=module-load
-a always,exit -F arch=b32 -S delete_module -F key=module-unload
-a always,exit -F arch=b64 -S delete_module -F key=module-unload
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/43-module-load.rules according to policy
  copy:
    dest: /etc/audit/rules.d/43-module-load.rules
    content: |
      ## These rules watch for kernel module insertion. By monitoring
      ## the syscall, we do not need any watches on programs.
      -a always,exit -F arch=b32 -S init_module,finit_module -F key=module-load
      -a always,exit -F arch=b64 -S init_module,finit_module -F key=module-load
      -a always,exit -F arch=b32 -S delete_module -F key=module-unload
      -a always,exit -F arch=b64 -S delete_module -F key=module-unload
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82838-4
    - NIST-800-53-AU-2(a)
    - audit_module_load
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20These%20rules%20watch%20for%20kernel%20module%20insertion.%20By%20monitoring%0A%23%23%20the%20syscall%2C%20we%20do%20not%20need%20any%20watches%20on%20programs.%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20init_module%2Cfinit_module%20-F%20key%3Dmodule-load%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20init_module%2Cfinit_module%20-F%20key%3Dmodule-load%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20delete_module%20-F%20key%3Dmodule-unload%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20delete_module%20-F%20key%3Dmodule-unload%0A
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/43-module-load.rules

Rule   Configure auditing of successful file creations   [ref]

Ensure that successful attempts to create a file are audited. The following rules configure audit as described above:

## Successful file creation (open with O_CREAT)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b32 -S open -F a1&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b64 -S open -F a1&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b32 -S creat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b64 -S creat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-1-create-success.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-1-create-success.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load

Rationale:

Auditing of successful attempts to create a file helps in investigation of actions which happened on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_create_success
Identifiers and References

Identifiers:  CCE-82829-3

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-1-create-success.rules
## Successful file creation (open with O_CREAT)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b32 -S open -F a1&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b64 -S open -F a1&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b32 -S creat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
-a always,exit -F arch=b64 -S creat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-1-create-success.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-1-create-success.rules
    content: |
      ## Successful file creation (open with O_CREAT)
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
      -a always,exit -F arch=b32 -S open -F a1&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
      -a always,exit -F arch=b64 -S open -F a1&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
      -a always,exit -F arch=b32 -S creat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
      -a always,exit -F arch=b64 -S creat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82829-3
    - NIST-800-53-AU-2(a)
    - audit_create_success
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure auditing of successful file accesses   [ref]

Ensure that successful attempts to access a file are audited. The following rules configure audit as described above:

## Successful file access (any other opens) This has to go last.
## These next two are likely to result in a whole lot of events
-a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-access
-a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-access
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-3-access-success.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-3-access-success.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Auditing of successful attempts to access a file helps in investigation of activities performed on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_access_success
Identifiers and References

Identifiers:  CCE-82834-3

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-3-access-success.rules
## Successful file access (any other opens) This has to go last.
## These next two are likely to result in a whole lot of events
-a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-access
-a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-access
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-3-access-success.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-3-access-success.rules
    content: |
      ## Successful file access (any other opens) This has to go last.
      ## These next two are likely to result in a whole lot of events
      -a always,exit -F arch=b32 -S open,openat,open_by_handle_at -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-access
      -a always,exit -F arch=b64 -S open,openat,open_by_handle_at -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-access
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82834-3
    - NIST-800-53-AU-2(a)
    - audit_access_success
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Successful%20file%20access%20%28any%20other%20opens%29%20This%20has%20to%20go%20last.%0A%23%23%20These%20next%20two%20are%20likely%20to%20result%20in%20a%20whole%20lot%20of%20events%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%2Copenat%2Copen_by_handle_at%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-access%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%2Copenat%2Copen_by_handle_at%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-access
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-3-access-success.rules

Rule   Configure auditing of unsuccessful file creations   [ref]

Ensure that unsuccessful attempts to create a file are audited. The following rules configure audit as described above:

## Unsuccessful file creation (open with O_CREAT)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-1-create-failed.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-1-create-failed.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Unsuccessful file creations might be a sign of a malicious action being performed on the system. Keeping log of such events helps in monitoring and investigation of such actions.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_create_failed
Identifiers and References

Identifiers:  CCE-82374-0

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-1-create-failed.rules
## Unsuccessful file creation (open with O_CREAT)
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
-a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-1-create-failed.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-1-create-failed.rules
    content: |
      ## Unsuccessful file creation (open with O_CREAT)
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b32 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b64 -S open -F a1&0100 -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
      -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-create
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82374-0
    - NIST-800-53-AU-2(a)
    - audit_create_failed
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Unsuccessful%20file%20creation%20%28open%20with%20O_CREAT%29%0A%23%23%20/etc/audit/rules.d/30-ospp-v42-1-create-failed.rules%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%26amp%3B0100%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%26amp%3B0100%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%26amp%3B0100%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%26amp%3B0100%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20creat%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20creat%20-F%20exit%3D-EACCES%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%26amp%3B0100%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%26amp%3B0100%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%26amp%3B0100%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%26amp%3B0100%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20creat%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20creat%20-F%20exit%3D-EPERM%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dunsuccessful-create%0A
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-1-create-failed.rules 

Rule   Configure auditing of successful file deletions   [ref]

Ensure that successful attempts to delete a file are audited. The following rules configure audit as described above:

## Successful file delete
-a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
-a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-4-delete-success.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-4-delete-success.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Auditing of successful attempts to delete a file may help in monitoring and investigation of activities performed on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_delete_success
Identifiers and References

Identifiers:  CCE-82836-8

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000461-GPOS-00205, SRG-OS-000468-GPOS-00212, SRG-OS-000467-GPOS-00211



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-4-delete-success.rules
## Successful file delete
-a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
-a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-4-delete-success.rules according
    to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-4-delete-success.rules
    content: |
      ## Successful file delete
      -a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
      -a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82836-8
    - NIST-800-53-AU-2(a)
    - audit_delete_success
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20Successful%20file%20delete%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20unlink%2Cunlinkat%2Crename%2Crenameat%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-delete%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20unlink%2Cunlinkat%2Crename%2Crenameat%20-F%20success%3D1%20-F%20auid%26gt%3B%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsuccessful-delete
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42-4-delete-success.rules

Rule   Perform general configuration of Audit for OSPP   [ref]

Configure some basic Audit parameters specific for OSPP profile. In particular, configure Audit to watch for direct modification of files storing system user and group information, and usage of applications with special rights which can change system configuration. Further audited events include access to audit log it self, attempts to Alter Process and Session Initiation Information, and attempts to modify MAC controls. The following rules configure audit as described above:

## The purpose of these rules is to meet the requirements for Operating
## System Protection Profile (OSPP)v4.2. These rules depends on having
## the following rule files copied to /etc/audit/rules.d:
##
## 10-base-config.rules, 11-loginuid.rules,
## 30-ospp-v42-1-create-failed.rules, 30-ospp-v42-1-create-success.rules,
## 30-ospp-v42-2-modify-failed.rules, 30-ospp-v42-2-modify-success.rules,
## 30-ospp-v42-3-access-failed.rules, 30-ospp-v42-3-access-success.rules,
## 30-ospp-v42-4-delete-failed.rules, 30-ospp-v42-4-delete-success.rules,
## 30-ospp-v42-5-perm-change-failed.rules,
## 30-ospp-v42-5-perm-change-success.rules,
## 30-ospp-v42-6-owner-change-failed.rules,
## 30-ospp-v42-6-owner-change-success.rules
##
## original copies may be found in /usr/share/audit/sample-rules/


## User add delete modify. This is covered by pam. However, someone could
## open a file and directly create or modify a user, so we'll watch passwd and
## shadow for writes
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b32 -S open -F a1&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S open -F a1&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b32 -S open -F a1&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S open -F a1&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify

## User enable and disable. This is entirely handled by pam.

## Group add delete modify. This is covered by pam. However, someone could
## open a file and directly create or modify a user, so we'll watch group and
## gshadow for writes
-a always,exit -F path=/etc/passwd -F perm=wa -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F path=/etc/shadow -F perm=wa -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F path=/etc/group -F perm=wa -F auid>=1000 -F auid!=unset -F key=group-modify
-a always,exit -F path=/etc/gshadow -F perm=wa -F auid>=1000 -F auid!=unset -F key=group-modify


## Use of special rights for config changes. This would be use of setuid
## programs that relate to user accts. This is not all setuid apps because
## requirements are only for ones that affect system configuration.
-a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/sbin/usernetctl -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/sbin/seunshare -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/newuidmap -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/newgidmap -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/at -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes

## Privilege escalation via su or sudo. This is entirely handled by pam.

## Audit log access
-a always,exit -F dir=/var/log/audit/ -F perm=r -F auid>=1000 -F auid!=unset -F key=access-audit-trail
## Attempts to Alter Process and Session Initiation Information
-a always,exit -F path=/var/run/utmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session
-a always,exit -F path=/var/log/btmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session
-a always,exit -F path=/var/log/wtmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session

## Attempts to modify MAC controls
-a always,exit -F dir=/etc/selinux/ -F perm=wa -F auid>=1000 -F auid!=unset -F key=MAC-policy

## Software updates. This is entirely handled by rpm.

## System start and shutdown. This is entirely handled by systemd

## Kernel Module loading. This is handled in 43-module-load.rules

## Application invocation. The requirements list an optional requirement
## FPT_SRP_EXT.1 Software Restriction Policies. This event is intended to
## state results from that policy. This would be handled entirely by
## that daemon.

The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Auditing of events listed in the description provides data for monitoring and investigation of potentially malicious events e.g. tampering with Audit logs, malicious access to files storing information about system users and groups etc.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_ospp_general
Identifiers and References

Identifiers:  CCE-82373-2

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000004-GPOS-00004, SRG-OS-000241-GPOS-00091, SRG-OS-000476-GPOS-00221, SRG-OS-000327-GPOS-00127, SRG-OS-000475-GPOS-00220, SRG-OS-000239-GPOS-00089, SRG-OS-000274-GPOS-00104, SRG-OS-000275-GPOS-00105, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42.rules
## The purpose of these rules is to meet the requirements for Operating
## System Protection Profile (OSPP)v4.2. These rules depends on having
## the following rule files copied to /etc/audit/rules.d:
##
## 10-base-config.rules, 11-loginuid.rules,
## 30-ospp-v42-1-create-failed.rules, 30-ospp-v42-1-create-success.rules,
## 30-ospp-v42-2-modify-failed.rules, 30-ospp-v42-2-modify-success.rules,
## 30-ospp-v42-3-access-failed.rules, 30-ospp-v42-3-access-success.rules,
## 30-ospp-v42-4-delete-failed.rules, 30-ospp-v42-4-delete-success.rules,
## 30-ospp-v42-5-perm-change-failed.rules,
## 30-ospp-v42-5-perm-change-success.rules,
## 30-ospp-v42-6-owner-change-failed.rules,
## 30-ospp-v42-6-owner-change-success.rules
##
## original copies may be found in /usr/share/audit/sample-rules/


## User add delete modify. This is covered by pam. However, someone could
## open a file and directly create or modify a user, so we'll watch passwd and
## shadow for writes
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b32 -S open -F a1&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S open -F a1&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b32 -S open -F a1&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F arch=b64 -S open -F a1&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify

## User enable and disable. This is entirely handled by pam.

## Group add delete modify. This is covered by pam. However, someone could
## open a file and directly create or modify a user, so we'll watch group and
## gshadow for writes
-a always,exit -F path=/etc/passwd -F perm=wa -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F path=/etc/shadow -F perm=wa -F auid>=1000 -F auid!=unset -F key=user-modify
-a always,exit -F path=/etc/group -F perm=wa -F auid>=1000 -F auid!=unset -F key=group-modify
-a always,exit -F path=/etc/gshadow -F perm=wa -F auid>=1000 -F auid!=unset -F key=group-modify


## Use of special rights for config changes. This would be use of setuid
## programs that relate to user accts. This is not all setuid apps because
## requirements are only for ones that affect system configuration.
-a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/sbin/usernetctl -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/sbin/seunshare -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/newuidmap -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/newgidmap -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
-a always,exit -F path=/usr/bin/at -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes

## Privilege escalation via su or sudo. This is entirely handled by pam.

## Audit log access
-a always,exit -F dir=/var/log/audit/ -F perm=r -F auid>=1000 -F auid!=unset -F key=access-audit-trail
## Attempts to Alter Process and Session Initiation Information
-a always,exit -F path=/var/run/utmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session
-a always,exit -F path=/var/log/btmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session
-a always,exit -F path=/var/log/wtmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session

## Attempts to modify MAC controls
-a always,exit -F dir=/etc/selinux/ -F perm=wa -F auid>=1000 -F auid!=unset -F key=MAC-policy

## Software updates. This is entirely handled by rpm.

## System start and shutdown. This is entirely handled by systemd

## Kernel Module loading. This is handled in 43-module-load.rules

## Application invocation. The requirements list an optional requirement
## FPT_SRP_EXT.1 Software Restriction Policies. This event is intended to
## state results from that policy. This would be handled entirely by
## that daemon.
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42.rules according to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42.rules
    content: |
      ## The purpose of these rules is to meet the requirements for Operating
      ## System Protection Profile (OSPP)v4.2. These rules depends on having
      ## the following rule files copied to /etc/audit/rules.d:
      ##
      ## 10-base-config.rules, 11-loginuid.rules,
      ## 30-ospp-v42-1-create-failed.rules, 30-ospp-v42-1-create-success.rules,
      ## 30-ospp-v42-2-modify-failed.rules, 30-ospp-v42-2-modify-success.rules,
      ## 30-ospp-v42-3-access-failed.rules, 30-ospp-v42-3-access-success.rules,
      ## 30-ospp-v42-4-delete-failed.rules, 30-ospp-v42-4-delete-success.rules,
      ## 30-ospp-v42-5-perm-change-failed.rules,
      ## 30-ospp-v42-5-perm-change-success.rules,
      ## 30-ospp-v42-6-owner-change-failed.rules,
      ## 30-ospp-v42-6-owner-change-success.rules
      ##
      ## original copies may be found in /usr/share/audit/sample-rules/


      ## User add delete modify. This is covered by pam. However, someone could
      ## open a file and directly create or modify a user, so we'll watch passwd and
      ## shadow for writes
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b32 -S open -F a1&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b64 -S open -F a1&03 -F path=/etc/passwd -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b32 -S openat,open_by_handle_at -F a2&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b64 -S openat,open_by_handle_at -F a2&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b32 -S open -F a1&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F arch=b64 -S open -F a1&03 -F path=/etc/shadow -F auid>=1000 -F auid!=unset -F key=user-modify

      ## User enable and disable. This is entirely handled by pam.

      ## Group add delete modify. This is covered by pam. However, someone could
      ## open a file and directly create or modify a user, so we'll watch group and
      ## gshadow for writes
      -a always,exit -F path=/etc/passwd -F perm=wa -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F path=/etc/shadow -F perm=wa -F auid>=1000 -F auid!=unset -F key=user-modify
      -a always,exit -F path=/etc/group -F perm=wa -F auid>=1000 -F auid!=unset -F key=group-modify
      -a always,exit -F path=/etc/gshadow -F perm=wa -F auid>=1000 -F auid!=unset -F key=group-modify


      ## Use of special rights for config changes. This would be use of setuid
      ## programs that relate to user accts. This is not all setuid apps because
      ## requirements are only for ones that affect system configuration.
      -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/sbin/usernetctl -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/sbin/seunshare -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/newuidmap -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/newgidmap -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes
      -a always,exit -F path=/usr/bin/at -F perm=x -F auid>=1000 -F auid!=unset -F key=special-config-changes

      ## Privilege escalation via su or sudo. This is entirely handled by pam.

      ## Audit log access
      -a always,exit -F dir=/var/log/audit/ -F perm=r -F auid>=1000 -F auid!=unset -F key=access-audit-trail
      ## Attempts to Alter Process and Session Initiation Information
      -a always,exit -F path=/var/run/utmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session
      -a always,exit -F path=/var/log/btmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session
      -a always,exit -F path=/var/log/wtmp -F perm=wa -F auid>=1000 -F auid!=unset -F key=session

      ## Attempts to modify MAC controls
      -a always,exit -F dir=/etc/selinux/ -F perm=wa -F auid>=1000 -F auid!=unset -F key=MAC-policy

      ## Software updates. This is entirely handled by rpm.

      ## System start and shutdown. This is entirely handled by systemd

      ## Kernel Module loading. This is handled in 43-module-load.rules

      ## Application invocation. The requirements list an optional requirement
      ## FPT_SRP_EXT.1 Software Restriction Policies. This event is intended to
      ## state results from that policy. This would be handled entirely by
      ## that daemon.
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82373-2
    - NIST-800-53-AU-2(a)
    - audit_ospp_general
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%23%20The%20purpose%20of%20these%20rules%20is%20to%20meet%20the%20requirements%20for%20Operating%0A%23%23%20System%20Protection%20Profile%20%28OSPP%29v4.2.%20These%20rules%20depends%20on%20having%0A%23%23%20the%20following%20rule%20files%20copied%20to%20/etc/audit/rules.d%3A%0A%23%23%0A%23%23%2010-base-config.rules%2C%2011-loginuid.rules%2C%0A%23%23%2030-ospp-v42-1-create-failed.rules%2C%2030-ospp-v42-1-create-success.rules%2C%0A%23%23%2030-ospp-v42-2-modify-failed.rules%2C%2030-ospp-v42-2-modify-success.rules%2C%0A%23%23%2030-ospp-v42-3-access-failed.rules%2C%2030-ospp-v42-3-access-success.rules%2C%0A%23%23%2030-ospp-v42-4-delete-failed.rules%2C%2030-ospp-v42-4-delete-success.rules%2C%0A%23%23%2030-ospp-v42-5-perm-change-failed.rules%2C%0A%23%23%2030-ospp-v42-5-perm-change-success.rules%2C%0A%23%23%2030-ospp-v42-6-owner-change-failed.rules%2C%0A%23%23%2030-ospp-v42-6-owner-change-success.rules%0A%23%23%0A%23%23%20original%20copies%20may%20be%20found%20in%20/usr/share/audit/sample-rules/%0A%0A%0A%23%23%20User%20add%20delete%20modify.%20This%20is%20covered%20by%20pam.%20However%2C%20someone%20could%0A%23%23%20open%20a%20file%20and%20directly%20create%20or%20modify%20a%20user%2C%20so%20we%27ll%20watch%20passwd%20and%0A%23%23%20shadow%20for%20writes%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2603%20-F%20path%3D/etc/passwd%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2603%20-F%20path%3D/etc/passwd%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%2603%20-F%20path%3D/etc/passwd%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%2603%20-F%20path%3D/etc/passwd%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2603%20-F%20path%3D/etc/shadow%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20openat%2Copen_by_handle_at%20-F%20a2%2603%20-F%20path%3D/etc/shadow%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20open%20-F%20a1%2603%20-F%20path%3D/etc/shadow%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20open%20-F%20a1%2603%20-F%20path%3D/etc/shadow%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A%0A%23%23%20User%20enable%20and%20disable.%20This%20is%20entirely%20handled%20by%20pam.%0A%0A%23%23%20Group%20add%20delete%20modify.%20This%20is%20covered%20by%20pam.%20However%2C%20someone%20could%0A%23%23%20open%20a%20file%20and%20directly%20create%20or%20modify%20a%20user%2C%20so%20we%27ll%20watch%20group%20and%0A%23%23%20gshadow%20for%20writes%0A-a%20always%2Cexit%20-F%20path%3D/etc/passwd%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20path%3D/etc/shadow%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Duser-modify%0A-a%20always%2Cexit%20-F%20path%3D/etc/group%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dgroup-modify%0A-a%20always%2Cexit%20-F%20path%3D/etc/gshadow%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dgroup-modify%0A%0A%0A%23%23%20Use%20of%20special%20rights%20for%20config%20changes.%20This%20would%20be%20use%20of%20setuid%0A%23%23%20programs%20that%20relate%20to%20user%20accts.%20This%20is%20not%20all%20setuid%20apps%20because%0A%23%23%20requirements%20are%20only%20for%20ones%20that%20affect%20system%20configuration.%0A-a%20always%2Cexit%20-F%20path%3D/usr/sbin/unix_chkpwd%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/sbin/usernetctl%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/sbin/userhelper%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/sbin/seunshare%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/mount%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/newgrp%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/newuidmap%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/gpasswd%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/newgidmap%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/umount%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/passwd%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/crontab%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A-a%20always%2Cexit%20-F%20path%3D/usr/bin/at%20-F%20perm%3Dx%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dspecial-config-changes%0A%0A%23%23%20Privilege%20escalation%20via%20su%20or%20sudo.%20This%20is%20entirely%20handled%20by%20pam.%0A%0A%23%23%20Audit%20log%20access%0A-a%20always%2Cexit%20-F%20dir%3D/var/log/audit/%20-F%20perm%3Dr%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Daccess-audit-trail%0A%23%23%20Attempts%20to%20Alter%20Process%20and%20Session%20Initiation%20Information%0A-a%20always%2Cexit%20-F%20path%3D/var/run/utmp%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsession%0A-a%20always%2Cexit%20-F%20path%3D/var/log/btmp%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsession%0A-a%20always%2Cexit%20-F%20path%3D/var/log/wtmp%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3Dsession%0A%0A%23%23%20Attempts%20to%20modify%20MAC%20controls%0A-a%20always%2Cexit%20-F%20dir%3D/etc/selinux/%20-F%20perm%3Dwa%20-F%20auid%3E%3D1000%20-F%20auid%21%3Dunset%20-F%20key%3DMAC-policy%0A%0A%23%23%20Software%20updates.%20This%20is%20entirely%20handled%20by%20rpm.%0A%0A%23%23%20System%20start%20and%20shutdown.%20This%20is%20entirely%20handled%20by%20systemd%0A%0A%23%23%20Kernel%20Module%20loading.%20This%20is%20handled%20in%2043-module-load.rules%0A%0A%23%23%20Application%20invocation.%20The%20requirements%20list%20an%20optional%20requirement%0A%23%23%20FPT_SRP_EXT.1%20Software%20Restriction%20Policies.%20This%20event%20is%20intended%20to%0A%23%23%20state%20results%20from%20that%20policy.%20This%20would%20be%20handled%20entirely%20by%0A%23%23%20that%20daemon.%0A
        filesystem: root
        mode: 0600
        path: /etc/audit/rules.d/30-ospp-v42.rules

Rule   Configure auditing of unsuccessful ownership changes   [ref]

Ensure that unsuccessful attempts to change an ownership of files or directories are audited. The following rules configure audit as described above:

## Unsuccessful ownership change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
-a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
-a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
The Audit package provides pre-configured rules in /usr/share/audit/sample-rules. The above content can be found in /usr/share/audit/sample-rules/30-ospp-v42-6-owner-change-failed.rules. To deploy this configuration, it is recommended to copy it over to the /etc/audit/rules.d/ directory:
cp /usr/share/audit/sample-rules/30-ospp-v42-6-owner-change-failed.rules /etc/audit/rules.d/
Load new Audit rules into kernel by running:
augenrules --load
Note: This rule utilizes a file provided by Audit package to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.

Rationale:

Unsuccessful attempts to change an ownership of files or directories might be signs of a malicious activity. Having such events audited helps in monitoring and investigation of such activities.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_owner_change_failed
Identifiers and References

Identifiers:  CCE-82384-9

References:  AU-2(a), FAU_GEN.1.1.c, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000474-GPOS-00219, SRG-OS-000475-GPOS-00220, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033



Complexity:low
Disruption:low
Strategy:restrict


cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-6-owner-change-failed.rules
## Unsuccessful ownership change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
-a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
-a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
EOF

augenrules --load


Complexity:low
Disruption:low
Strategy:restrict
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-6-owner-change-failed.rules
    according to policy
  copy:
    dest: /etc/audit/rules.d/30-ospp-v42-6-owner-change-failed.rules
    content: |
      ## Unsuccessful ownership change
      -a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
      -a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
      -a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
      -a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
    force: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82384-9
    - NIST-800-53-AU-2(a)
    - audit_owner_change_failed
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
Group   Configure auditd Data Retention   Group contains 6 rules

[ref]   The audit system writes data to /var/log/audit/audit.log. By default, auditd rotates 5 logs by size (6MB), retaining a maximum of 30MB of data in total, and refuses to write entries when the disk is too full. This minimizes the risk of audit data filling its partition and impacting other services. This also minimizes the risk of the audit daemon temporarily disabling the system if it cannot write audit log (which it can be configured to do). For a busy system or a system which is thoroughly auditing system activity, the default settings for data retention may be insufficient. The log file size needed will depend heavily on what types of events are being audited. First configure auditing to log all the events of interest. Then monitor the log size manually for awhile to determine what file size will allow you to keep the required data for the correct time period.

Using a dedicated partition for /var/log/audit prevents the auditd logs from disrupting system functionality if they fill, and, more importantly, prevents other activity in /var from filling the partition and stopping the audit trail. (The audit logs are size-limited and therefore unlikely to grow without bound unless configured to do so.) Some machines may have requirements that no actions occur which cannot be audited. If this is the case, then auditd can be configured to halt the machine if it runs out of space. Note: Since older logs are rotated, configuring auditd this way does not prevent older logs from being rotated away before they can be viewed. If your system is configured to halt when logging cannot be performed, make sure this can never happen under normal circumstances! Ensure that /var/log/audit is on its own partition, and that this partition is larger than the maximum amount of data auditd will retain normally.

Rule   Configure auditd flush priority   [ref]

The auditd service can be configured to synchronously write audit event data to disk. Add or correct the following line in /etc/audit/auditd.conf to ensure that audit event data is fully synchronized with the log files on the disk:

flush = incremental_async

Rationale:

Audit data should be synchronously written to disk to ensure log integrity. These parameters assure that all audit event data is fully synchronized with the log files on the disk.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_data_retention_flush
Identifiers and References

Identifiers:  CCE-80680-2

References:  1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, CCI-001576, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, AU-11, CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000480-GPOS-00227




var_auditd_flush="incremental_async"

AUDITCONFIG=/etc/audit/auditd.conf

# if flush is present, flush param edited to var_auditd_flush
# else flush param is defined by var_auditd_flush
#
# the freq param is only used for values 'incremental' and 'incremental_async' and will be
# commented out if flush != incremental or flush != incremental_async
#
# if flush == incremental or flush == incremental_async && freq param is not defined, it 
# will be defined as the package-default value of 20

grep -q ^flush $AUDITCONFIG && \
  sed -i 's/^flush.*/flush = '"$var_auditd_flush"'/g' $AUDITCONFIG
if ! [ $? -eq 0 ]; then
  echo "flush = $var_auditd_flush" >> $AUDITCONFIG
fi

if ! [ "$var_auditd_flush" == "incremental" ] && ! [ "$var_auditd_flush" == "incremental_async" ]; then
  sed -i 's/^freq/##freq/g' $AUDITCONFIG
elif [ "$var_auditd_flush" == "incremental" ] || [ "$var_auditd_flush" == "incremental_async" ]; then
  grep -q freq $AUDITCONFIG && \
    sed -i 's/^#\+freq/freq/g' $AUDITCONFIG
  if ! [ $? -eq 0 ]; then
    echo "freq = 20" >> $AUDITCONFIG
  fi
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_auditd_flush # promote to variable
  set_fact:
    var_auditd_flush: !!str incremental_async
  tags:
    - always

- name: Configure auditd Flush Priority
  lineinfile:
    dest: /etc/audit/auditd.conf
    regexp: ^\s*flush\s*=\s*.*$
    line: flush = {{ var_auditd_flush }}
    state: present
    create: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80680-2
    - NIST-800-171-3.3.1
    - NIST-800-53-AU-11
    - NIST-800-53-CM-6(a)
    - auditd_data_retention_flush
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20incremental_async%0Afreq%20%3D%2050%0Amax_log_file%20%3D%208%0Anum_logs%20%3D%205%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20ROTATE%0Aspace_left%20%3D%2075%0Aspace_left_action%20%3D%20SYSLOG%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20root%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20SUSPEND%0Adisk_full_action%20%3D%20SUSPEND%0Adisk_error_action%20%3D%20SUSPEND%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20SYSLOG%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d%0A
        filesystem: root
        mode: 0640
        path: /etc/audit/auditd.conf

Rule   Set number of records to cause an explicit flush to audit logs   [ref]

To configure Audit daemon to issue an explicit flush to disk command after writing 50 records, set freq to 50 in /etc/audit/auditd.conf.

Rationale:

If option freq isn't set to 50, the flush to disk may happen after higher number of records, increasing the danger of audit loss.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_freq
Identifiers and References

Identifiers:  CCE-82258-5

References:  FAU_GEN.1, SRG-OS-000051-GPOS-00024



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/audit/auditd.conf" ] ; then
    LC_ALL=C sed -i "/^\s*freq\s*=\s*/Id" "/etc/audit/auditd.conf"
else
    touch "/etc/audit/auditd.conf"
fi
cp "/etc/audit/auditd.conf" "/etc/audit/auditd.conf.bak"
# Insert at the end of the file
printf '%s\n' "freq = 50" >> "/etc/audit/auditd.conf"
# Clean up after ourselves.
rm "/etc/audit/auditd.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Set number of records to cause an explicit flush to audit logs
  block:

    - name: Deduplicate values from /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: false
        regexp: (?i)^\s*freq\s*=\s*
        state: absent

    - name: Insert correct line to /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: true
        line: freq = 50
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82258-5
    - auditd_freq
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20incremental_async%0Afreq%20%3D%2050%0Amax_log_file%20%3D%208%0Anum_logs%20%3D%205%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20ROTATE%0Aspace_left%20%3D%2075%0Aspace_left_action%20%3D%20SYSLOG%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20root%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20SUSPEND%0Adisk_full_action%20%3D%20SUSPEND%0Adisk_error_action%20%3D%20SUSPEND%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20SYSLOG%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d%0A
        filesystem: root
        mode: 0640
        path: /etc/audit/auditd.conf

Rule   Include Local Events in Audit Logs   [ref]

To configure Audit daemon to include local events in Audit logs, set local_events to yes in /etc/audit/auditd.conf. This is the default setting.

Rationale:

If option local_events isn't set to yes only events from network will be aggregated.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_local_events
Identifiers and References

Identifiers:  CCE-82233-8

References:  FAU_GEN.1.1.c, SRG-OS-000062-GPOS-00031



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/audit/auditd.conf" ] ; then
    LC_ALL=C sed -i "/^\s*local_events\s*=\s*/Id" "/etc/audit/auditd.conf"
else
    touch "/etc/audit/auditd.conf"
fi
cp "/etc/audit/auditd.conf" "/etc/audit/auditd.conf.bak"
# Insert at the end of the file
printf '%s\n' "local_events = yes" >> "/etc/audit/auditd.conf"
# Clean up after ourselves.
rm "/etc/audit/auditd.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Include Local Events in Audit Logs
  block:

    - name: Deduplicate values from /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: false
        regexp: (?i)^\s*local_events\s*=\s*
        state: absent

    - name: Insert correct line to /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: true
        line: local_events = yes
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82233-8
    - auditd_local_events
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20incremental_async%0Afreq%20%3D%2050%0Amax_log_file%20%3D%208%0Anum_logs%20%3D%205%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20ROTATE%0Aspace_left%20%3D%2075%0Aspace_left_action%20%3D%20SYSLOG%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20root%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20SUSPEND%0Adisk_full_action%20%3D%20SUSPEND%0Adisk_error_action%20%3D%20SUSPEND%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20SYSLOG%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d%0A
        filesystem: root
        mode: 0640
        path: /etc/audit/auditd.conf

Rule   Set hostname as computer node name in audit logs   [ref]

To configure Audit daemon to use value returned by gethostname syscall as computer node name in the audit events, set name_format to hostname in /etc/audit/auditd.conf.

Rationale:

If option name_format is left at its default value of none, audit events from different computers may be hard to distinguish.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_name_format
Identifiers and References

Identifiers:  CCE-82897-0

References:  CCI-001851, FAU_GEN.1, SRG-OS-000039-GPOS-00017, SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/audit/auditd.conf" ] ; then
    LC_ALL=C sed -i "/^\s*name_format\s*=\s*/Id" "/etc/audit/auditd.conf"
else
    touch "/etc/audit/auditd.conf"
fi
cp "/etc/audit/auditd.conf" "/etc/audit/auditd.conf.bak"
# Insert at the end of the file
printf '%s\n' "name_format = hostname" >> "/etc/audit/auditd.conf"
# Clean up after ourselves.
rm "/etc/audit/auditd.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Set hostname as computer node name in audit logs
  block:

    - name: Deduplicate values from /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: false
        regexp: (?i)^\s*name_format\s*=\s*
        state: absent

    - name: Insert correct line to /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: true
        line: name_format = hostname
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82897-0
    - auditd_name_format
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20incremental_async%0Afreq%20%3D%2050%0Amax_log_file%20%3D%208%0Anum_logs%20%3D%205%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20ROTATE%0Aspace_left%20%3D%2075%0Aspace_left_action%20%3D%20SYSLOG%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20root%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20SUSPEND%0Adisk_full_action%20%3D%20SUSPEND%0Adisk_error_action%20%3D%20SUSPEND%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20SYSLOG%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d%0A
        filesystem: root
        mode: 0640
        path: /etc/audit/auditd.conf

Rule   Resolve information before writing to audit logs   [ref]

To configure Audit daemon to resolve all uid, gid, syscall, architecture, and socket address information before writing the events to disk, set log_format to ENRICHED in /etc/audit/auditd.conf.

Rationale:

If option log_format isn't set to ENRICHED, the audit records will be stored in a format exactly as the kernel sends them.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_log_format
Identifiers and References

Identifiers:  CCE-82201-5

References:  FAU_GEN.1, SRG-OS-000255-GPOS-00096



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/audit/auditd.conf" ] ; then
    LC_ALL=C sed -i "/^\s*log_format\s*=\s*/Id" "/etc/audit/auditd.conf"
else
    touch "/etc/audit/auditd.conf"
fi
cp "/etc/audit/auditd.conf" "/etc/audit/auditd.conf.bak"
# Insert at the end of the file
printf '%s\n' "log_format = ENRICHED" >> "/etc/audit/auditd.conf"
# Clean up after ourselves.
rm "/etc/audit/auditd.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Resolve information before writing to audit logs
  block:

    - name: Deduplicate values from /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: false
        regexp: (?i)^\s*log_format\s*=\s*
        state: absent

    - name: Insert correct line to /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: true
        line: log_format = ENRICHED
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82201-5
    - auditd_log_format
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20incremental_async%0Afreq%20%3D%2050%0Amax_log_file%20%3D%208%0Anum_logs%20%3D%205%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20ROTATE%0Aspace_left%20%3D%2075%0Aspace_left_action%20%3D%20SYSLOG%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20root%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20SUSPEND%0Adisk_full_action%20%3D%20SUSPEND%0Adisk_error_action%20%3D%20SUSPEND%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20SYSLOG%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d%0A
        filesystem: root
        mode: 0640
        path: /etc/audit/auditd.conf

Rule   Write Audit Logs to the Disk   [ref]

To configure Audit daemon to write Audit logs to the disk, set write_logs to yes in /etc/audit/auditd.conf. This is the default setting.

Rationale:

If write_logs isn't set to yes, the Audit logs will not be written to the disk.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_write_logs
Identifiers and References

Identifiers:  CCE-82366-6

References:  FAU_GEN.1.1.c, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/audit/auditd.conf" ] ; then
    LC_ALL=C sed -i "/^\s*write_logs\s*=\s*/Id" "/etc/audit/auditd.conf"
else
    touch "/etc/audit/auditd.conf"
fi
cp "/etc/audit/auditd.conf" "/etc/audit/auditd.conf.bak"
# Insert at the end of the file
printf '%s\n' "write_logs = yes" >> "/etc/audit/auditd.conf"
# Clean up after ourselves.
rm "/etc/audit/auditd.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Write Audit Logs to the Disk
  block:

    - name: Deduplicate values from /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: false
        regexp: (?i)^\s*write_logs\s*=\s*
        state: absent

    - name: Insert correct line to /etc/audit/auditd.conf
      lineinfile:
        path: /etc/audit/auditd.conf
        create: true
        line: write_logs = yes
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82366-6
    - auditd_write_logs
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20incremental_async%0Afreq%20%3D%2050%0Amax_log_file%20%3D%208%0Anum_logs%20%3D%205%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20ROTATE%0Aspace_left%20%3D%2075%0Aspace_left_action%20%3D%20SYSLOG%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20root%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20SUSPEND%0Adisk_full_action%20%3D%20SUSPEND%0Adisk_error_action%20%3D%20SUSPEND%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20SYSLOG%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d%0A
        filesystem: root
        mode: 0640
        path: /etc/audit/auditd.conf

Rule   Ensure the audit Subsystem is Installed   [ref]

The audit package should be installed.

Rationale:

The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_audit_installed
Identifiers and References

Identifiers:  CCE-81043-2

References:  NT28(R50), 4.1.1.1, AC-7(a), AU-7(1), AU-7(2), AU-14, AU-12(2), AU-2(a), CM-6(a), SRG-OS-000480-GPOS-00227, SRG-OS-000122-GPOS-00063



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "audit" ; then
    yum install -y "audit"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure audit is installed
  package:
    name: audit
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81043-2
    - NIST-800-53-AC-7(a)
    - NIST-800-53-AU-12(2)
    - NIST-800-53-AU-14
    - NIST-800-53-AU-2(a)
    - NIST-800-53-AU-7(1)
    - NIST-800-53-AU-7(2)
    - NIST-800-53-CM-6(a)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_audit_installed


Complexity:low
Disruption:low
Strategy:enable
include install_audit

class install_audit {
  package { 'audit':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=audit

Rule   Enable auditd Service   [ref]

The auditd service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The auditd service can be enabled with the following command:

$ sudo systemctl enable auditd.service

Rationale:

Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the auditd service is active ensures audit records generated by the kernel are appropriately recorded.

Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_service_auditd_enabled
Identifiers and References

Identifiers:  CCE-80872-5

References:  4.1.1.2, 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 3.3.2, 3.3.6, CCI-000126, CCI-000130, CCI-000131, CCI-000132, CCI-000133, CCI-000134, CCI-000135, CCI-001464, CCI-001487, CCI-001814, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AC-2(g), AU-3, AU-10, AU-2(d), AU-12(c), AU-14(1), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.1, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000042-GPOS-00021, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000365-GPOS-00152, SRG-OS-000037-VMM-000150, SRG-OS-000063-VMM-000310, SRG-OS-000038-VMM-000160, SRG-OS-000039-VMM-000170, SRG-OS-000040-VMM-000180, SRG-OS-000041-VMM-000190



Complexity:low
Disruption:low
Strategy:enable

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" start 'auditd.service'
"$SYSTEMCTL_EXEC" enable 'auditd.service'


Complexity:low
Disruption:low
Strategy:enable
- name: Enable service auditd
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable service auditd
      service:
        name: auditd
        enabled: 'yes'
        state: started
      when:
        - '"audit" in ansible_facts.packages'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80872-5
    - CJIS-5.4.1.1
    - NIST-800-171-3.3.1
    - NIST-800-171-3.3.2
    - NIST-800-171-3.3.6
    - NIST-800-53-AC-2(g)
    - NIST-800-53-AC-6(9)
    - NIST-800-53-AU-10
    - NIST-800-53-AU-12(c)
    - NIST-800-53-AU-14(1)
    - NIST-800-53-AU-2(d)
    - NIST-800-53-AU-3
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-10.1
    - enable_strategy
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - service_auditd_enabled


Complexity:low
Disruption:low
Strategy:enable
include enable_auditd

class enable_auditd {
  service {'auditd':
    enable => true,
    ensure => 'running',
  }
}


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    systemd:
      units:
      - name: auditd.service
        enabled: true

Rule   Extend Audit Backlog Limit for the Audit Daemon   [ref]

To improve the kernel capacity to queue all log events, even those which occurred prior to the audit daemon, add the argument audit_backlog_limit=8192 to the default GRUB 2 command line for the Linux operating system in /etc/default/grub, in the manner below:

GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=VolGroup/LogVol06 rd.lvm.lv=VolGroup/lv_swap rhgb quiet rd.shell=0 audit=1 audit_backlog_limit=8192"

Warning:  The GRUB 2 configuration file, grub.cfg, is automatically updated each time a new kernel is installed. Note that any changes to /etc/default/grub require rebuilding the grub.cfg file. To update the GRUB 2 configuration file manually, use the
grub2-mkconfig -o
command as follows:
  • On BIOS-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
  • On UEFI-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Rationale:

audit_backlog_limit sets the queue length for audit events awaiting transfer to the audit daemon. Until the audit daemon is up and running, all log messages are stored in this queue. If the queue is overrun during boot process, the action defined by audit failure flag is taken.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_audit_backlog_limit_argument
Identifiers and References

Identifiers:  CCE-80943-4

References:  4.1.1.4, CM-6(a), SRG-OS-000254-GPOS-00095





# Correct grub2 kernelopts value using grub2-editenv
if ! grub2-editenv - list | grep -qE '^kernelopts=(.*\s)?audit_backlog_limit=8192(\s.*)?$'; then
  grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit_backlog_limit=8192"
fi


Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: get current kernel parameters
  command: /usr/bin/grub2-editenv - list
  register: kernelopts
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80943-4
    - NIST-800-53-CM-6(a)
    - grub2_audit_backlog_limit_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Update the bootloader menu
  command: /usr/bin/grub2-editenv - set "{{ item }} audit_backlog_limit=8192"
  with_items: '{{ kernelopts.stdout_lines | select(''match'', ''^kernelopts.*'') |
    list }}'
  when:
    - kernelopts.stdout_lines is defined
    - kernelopts.stdout_lines | length > 0
    - kernelopts.stdout | regex_search('^kernelopts=(?:.*\s)?audit_backlog_limit=8192(?:\s.*)?$',
      multiline=True) is none
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80943-4
    - NIST-800-53-CM-6(a)
    - grub2_audit_backlog_limit_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  kernelArguments:
    - audit_backlog_limit=8192

Rule   Enable Auditing for Processes Which Start Prior to the Audit Daemon   [ref]

To ensure all processes can be audited, even those which start prior to the audit daemon, add the argument audit=1 to the default GRUB 2 command line for the Linux operating system in /boot/grub2/grubenv, in the manner below:

# grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit=1"

Warning:  The GRUB 2 configuration file, grub.cfg, is automatically updated each time a new kernel is installed. Note that any changes to /etc/default/grub require rebuilding the grub.cfg file. To update the GRUB 2 configuration file manually, use the
grub2-mkconfig -o
command as follows:
  • On BIOS-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
  • On UEFI-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Rationale:

Each process on the system carries an "auditable" flag which indicates whether its activities can be audited. Although auditd takes care of enabling this for all processes which launch after it does, adding the kernel argument ensures it is set for every process during boot.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_audit_argument
Identifiers and References

Identifiers:  CCE-80825-3

References:  4.1.1.3, 1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.02, DSS05.03, DSS05.04, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, CCI-001464, CCI-000130, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AC-17(1), AU-14(1), AU-10, CM-6(a), IR-5(1), DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.3, SRG-OS-000254-GPOS-00095, SRG-OS-000254-VMM-000880





# Correct grub2 kernelopts value using grub2-editenv
if ! grub2-editenv - list | grep -qE '^kernelopts=(.*\s)?audit=1(\s.*)?$'; then
  grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit=1"
fi


Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: get current kernel parameters
  command: /usr/bin/grub2-editenv - list
  register: kernelopts
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80825-3
    - CJIS-5.4.1.1
    - NIST-800-171-3.3.1
    - NIST-800-53-AC-17(1)
    - NIST-800-53-AU-10
    - NIST-800-53-AU-14(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IR-5(1)
    - PCI-DSS-Req-10.3
    - grub2_audit_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Update the bootloader menu
  command: /usr/bin/grub2-editenv - set "{{ item }} audit=1"
  with_items: '{{ kernelopts.stdout_lines | select(''match'', ''^kernelopts.*'') |
    list }}'
  when:
    - kernelopts.stdout_lines is defined
    - kernelopts.stdout_lines | length > 0
    - kernelopts.stdout | regex_search('^kernelopts=(?:.*\s)?audit=1(?:\s.*)?$', multiline=True)
      is none
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80825-3
    - CJIS-5.4.1.1
    - NIST-800-171-3.3.1
    - NIST-800-53-AC-17(1)
    - NIST-800-53-AU-10
    - NIST-800-53-AU-14(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IR-5(1)
    - PCI-DSS-Req-10.3
    - grub2_audit_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  kernelArguments:
    - audit=1
Group   Installing and Maintaining Software   Group contains 9 groups and 41 rules

[ref]   The following sections contain information on security-relevant choices during the initial operating system installation process and the setup of software updates.

Group   System and Software Integrity   Group contains 4 groups and 11 rules

[ref]   System and software integrity can be gained by installing antivirus, increasing system encryption strength with FIPS, verifying installed software, enabling SELinux, installing an Intrusion Prevention System, etc. However, installing or enabling integrity checking tools cannot prevent intrusions, but they can detect that an intrusion may have occurred. Requirements for integrity checking may be highly dependent on the environment in which the system will be used. Snapshot-based approaches such as AIDE may induce considerable overhead in the presence of frequent software updates.

Group   Software Integrity Checking   Group contains 1 group and 1 rule

[ref]   Both the AIDE (Advanced Intrusion Detection Environment) software and the RPM package management system provide mechanisms for verifying the integrity of installed software. AIDE uses snapshots of file metadata (such as hashes) and compares these to current system files in order to detect changes.

The RPM package management system can conduct integrity checks by comparing information in its metadata database with files installed on the system.

Group   Verify Integrity with AIDE   Group contains 1 rule

[ref]   AIDE conducts integrity checks by comparing information about files with previously-gathered information. Ideally, the AIDE database is created immediately after initial system configuration, and then again after any software update. AIDE is highly configurable, with further configuration information located in /usr/share/doc/aide-VERSION.

Rule   Install AIDE   [ref]

The aide package can be installed with the following command:

$ sudo yum install aide

Rationale:

The AIDE package must be installed if it is to be available for integrity checking.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_aide_installed
Identifiers and References

Identifiers:  CCE-80844-4

References:  NT28(R51), 1.4.1, 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000363-GPOS-00150



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "aide" ; then
    yum install -y "aide"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure aide is installed
  package:
    name: aide
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80844-4
    - CJIS-5.10.1.3
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-11.5
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_aide_installed


Complexity:low
Disruption:low
Strategy:enable
include install_aide

class install_aide {
  package { 'aide':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=aide
Group   Federal Information Processing Standard (FIPS)   Group contains 2 rules

[ref]   The Federal Information Processing Standard (FIPS) is a computer security standard which is developed by the U.S. Government and industry working groups to validate the quality of cryptographic modules. The FIPS standard provides four security levels to ensure adequate coverage of different industries, implementation of cryptographic modules, and organizational sizes and requirements.

FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets industry and government requirements. For government systems, this allows Security Levels 1, 2, 3, or 4 for use on Red Hat Enterprise Linux 8.

See http://csrc.nist.gov/publications/PubsFIPS.html for more information.

Rule   Enable FIPS Mode   [ref]

To enable FIPS mode, run the following command:

fips-mode-setup --enable

The fips-mode-setup command will configure the system in FIPS mode by automatically configuring the following:
  • Setting the kernel FIPS mode flag (/proc/sys/crypto/fips_enabled) to 1
  • Creating /etc/system-fips
  • Setting the system crypto policy in /etc/crypto-policies/config to FIPS
  • Loading the Dracut fips module
Furthermore, the system running in FIPS mode should be FIPS certified by NIST.

Warning:  The system needs to be rebooted for these changes to take effect.
Warning:  System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.
Rationale:

Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_enable_fips_mode
Identifiers and References

Identifiers:  CCE-80942-6

References:  CCI-000068, CCI-000803, CCI-002450, SC-12(2), SC-12(3), IA-7, SC-13, CM-6(a), SC-12, SRG-OS-000478-GPOS-00223, SRG-OS-000396-GPOS-00176, SRG-OS-000120-VMM-000600, SRG-OS-000478-VMM-001980, SRG-OS-000396-VMM-001590




fips-mode-setup --enable


Complexity:medium
Disruption:medium
Reboot:true
Strategy:restrict
- name: enable fips mode
  command: /usr/bin/fips-mode-setup --enable
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80942-6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-7
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - enable_fips_mode
    - high_severity
    - medium_complexity
    - medium_disruption
    - reboot_required
    - restrict_strategy

Rule   Enable Dracut FIPS Module   [ref]

To enable FIPS mode, run the following command:

fips-mode-setup --enable
To enable FIPS, the system requires that the fips module is added in dracut configuration. Check if /etc/dracut.conf.d/40-fips.conf contain add_dracutmodules+=" fips "

Warning:  The system needs to be rebooted for these changes to take effect.
Warning:  System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.
Rationale:

Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_enable_dracut_fips_module
Identifiers and References

Identifiers:  CCE-82155-3

References:  CCI-000068, CCI-000803, CCI-002450, SC-12(2), SC-12(3), IA-7, SC-13, CM-6(a), SC-12, SRG-OS-000478-GPOS-00223, SRG-OS-000120-VMM-000600, SRG-OS-000478-VMM-001980, SRG-OS-000396-VMM-001590

Group   System Cryptographic Policies   Group contains 8 rules

[ref]   Linux has the capability to centrally configure cryptographic polices. The command update-crypto-policies is used to set the policy applicable for the various cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic policies will be the default policy used by these backends unless the application user configures them otherwise. When the system has been configured to use the centralized cryptographic policies, the administrator is assured that any application that utilizes the supported backends will follow a policy that adheres to the configured profile. Currently the supported backends are:

  • GnuTLS library
  • OpenSSL library
  • NSS library
  • OpenJDK
  • Libkrb5
  • BIND
  • OpenSSH
Applications and languages which rely on any of these backends will follow the system policies as well. Examples are apache httpd, nginx, php, and others.

Rule   Install crypto-policies package   [ref]

The crypto-policies package can be installed with the following command:

$ sudo yum install crypto-policies

Rationale:

Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_crypto-policies_installed
Identifiers and References

Identifiers:  CCE-82723-8

References:  FCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "crypto-policies" ; then
    yum install -y "crypto-policies"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure crypto-policies is installed
  package:
    name: crypto-policies
    state: present
  tags:
    - CCE-82723-8
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_crypto-policies_installed


Complexity:low
Disruption:low
Strategy:enable
include install_crypto-policies

class install_crypto-policies {
  package { 'crypto-policies':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=crypto-policies

Rule   Configure Libreswan to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. Libreswan is supported by system crypto policy, but the Libreswan configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the /etc/ipsec.conf includes the appropriate configuration file. In /etc/ipsec.conf, make sure that the following line is not commented out or superseded by later includes: include /etc/crypto-policies/back-ends/libreswan.config

Rationale:

Overriding the system crypto policy makes the behavior of the Libreswan service violate expectations, and makes system configuration more fragmented.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_libreswan_crypto_policy
Identifiers and References

Identifiers:  CCE-80937-6

References:  CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), SRG-OS-000033-GPOS-00014




function remediate_libreswan_crypto_policy() {
    CONFIG_FILE="/etc/ipsec.conf"
    if ! grep -qP "^\s*include\s+/etc/crypto-policies/back-ends/libreswan.config\s*(?:#.*)?$" "$CONFIG_FILE" ; then
        echo 'include /etc/crypto-policies/back-ends/libreswan.config' >> "$CONFIG_FILE"
    fi
    return 0
}

remediate_libreswan_crypto_policy


Complexity:low
Disruption:low
Strategy:restrict
- name: Configure Libreswan to use System Crypto Policy
  lineinfile:
    path: /etc/ipsec.conf
    line: include /etc/crypto-policies/back-ends/libreswan.config
    create: true
  tags:
    - CCE-80937-6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-MA-4(6)
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_libreswan_crypto_policy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure BIND to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. BIND is supported by crypto policy, but the BIND configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the /etc/named.conf includes the appropriate configuration: In the options section of /etc/named.conf, make sure that the following line is not commented out or superseded by later includes: include "/etc/crypto-policies/back-ends/bind.config";

Rationale:

Overriding the system crypto policy makes the behavior of the BIND service violate expectations, and makes system configuration more fragmented.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_bind_crypto_policy
Identifiers and References

Identifiers:  CCE-80934-3

References:  SC-13, SC-12(2), SC-12(3), SRG-OS-000423-GPOS-00187, SRG-OS-000426-GPOS-00190




function remediate_bind_crypto_policy() {
	CONFIG_FILE="/etc/named.conf"
	if test -f "$CONFIG_FILE"; then
		sed -i 's|options {|&\n\tinclude "/etc/crypto-policies/back-ends/bind.config";|' "$CONFIG_FILE"
		return 0
	else
		echo "Aborting remediation as '$CONFIG_FILE' was not even found." >&2
		return 1
	fi
}

remediate_bind_crypto_policy

Rule   Configure OpenSSL library to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. OpenSSL is supported by crypto policy, but the OpenSSL configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, you have to examine the OpenSSL config file available under /etc/pki/tls/openssl.cnf. This file has the ini format, and it enables crypto policy support if there is a [ crypto_policy ] section that contains the .include /etc/crypto-policies/back-ends/opensslcnf.config directive.

Rationale:

Overriding the system crypto policy makes the behavior of the Java runtime violates expectations, and makes system configuration more fragmented.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_openssl_crypto_policy
Identifiers and References

Identifiers:  CCE-80938-4

References:  AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), SRG-OS-000250-GPOS-00093




OPENSSL_CRYPTO_POLICY_SECTION='[ crypto_policy ]'
OPENSSL_CRYPTO_POLICY_SECTION_REGEX='\[\s*crypto_policy\s*\]'
OPENSSL_CRYPTO_POLICY_INCLUSION='.include /etc/crypto-policies/back-ends/opensslcnf.config'
OPENSSL_CRYPTO_POLICY_INCLUSION_REGEX='^\s*\.include\s*/etc/crypto-policies/back-ends/opensslcnf.config$'

function remediate_openssl_crypto_policy() {
	CONFIG_FILE="/etc/pki/tls/openssl.cnf"
	if test -f "$CONFIG_FILE"; then
		if ! grep -q "^\\s*$OPENSSL_CRYPTO_POLICY_SECTION_REGEX" "$CONFIG_FILE"; then
			printf '\n%s\n\n%s' "$OPENSSL_CRYPTO_POLICY_SECTION" "$OPENSSL_CRYPTO_POLICY_INCLUSION" >> "$CONFIG_FILE"
			return 0
		elif ! grep -q "^\\s*$OPENSSL_CRYPTO_POLICY_INCLUSION_REGEX" "$CONFIG_FILE"; then
			sed -i "s|$OPENSSL_CRYPTO_POLICY_SECTION_REGEX|&\\n\\n$OPENSSL_CRYPTO_POLICY_INCLUSION\\n|" "$CONFIG_FILE"
			return 0
		fi
	else
		echo "Aborting remediation as '$CONFIG_FILE' was not even found." >&2
		return 1
	fi
}

remediate_openssl_crypto_policy


Complexity:low
Disruption:medium
- name: Test for crypto_policy group
  command: grep '^\s*\[\s*crypto_policy\s*]' /etc/pki/tls/openssl.cnf
  register: test_crypto_policy_group
  ignore_errors: true
  changed_when: false
  check_mode: false
  tags:
    - CCE-80938-4
    - NIST-800-53-AC-17(2)
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-MA-4(6)
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_openssl_crypto_policy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
    - unknown_strategy

- name: Add .include for opensslcnf.config to crypto_policy section
  lineinfile:
    create: true
    insertafter: ^\s*\[\s*crypto_policy\s*]\s*
    line: .include /etc/crypto-policies/back-ends/opensslcnf.config
    path: /etc/pki/tls/openssl.cnf
  when:
    - test_crypto_policy_group.stdout is defined
    - test_crypto_policy_group.stdout | length > 0
  tags:
    - CCE-80938-4
    - NIST-800-53-AC-17(2)
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-MA-4(6)
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_openssl_crypto_policy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
    - unknown_strategy

- name: Add crypto_policy group and set include opensslcnf.config
  lineinfile:
    create: true
    line: |-
      [crypto_policy]
      .include /etc/crypto-policies/back-ends/opensslcnf.config
    path: /etc/pki/tls/openssl.cnf
  when:
    - test_crypto_policy_group.stdout is defined
    - test_crypto_policy_group.stdout | length < 1
  tags:
    - CCE-80938-4
    - NIST-800-53-AC-17(2)
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-MA-4(6)
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_openssl_crypto_policy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
    - unknown_strategy

Rule   Configure System Cryptography Policy   [ref]

To configure the system cryptography policy to use ciphers only from the FIPS:OSPP policy, run the following command:

$ sudo update-crypto-policies --set FIPS:OSPP
The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the /etc/crypto-policies/back-ends are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied. Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon.

Warning:  The system needs to be rebooted for these changes to take effect.
Warning:  System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.
Rationale:

Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_configure_crypto_policy
Identifiers and References

Identifiers:  CCE-80935-0

References:  1.10, 1.11, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174




var_system_crypto_policy="FIPS:OSPP"

stderr_of_call=$(update-crypto-policies --set ${var_system_crypto_policy} 2>&1 > /dev/null)
rc=$?

if test "$rc" = 127; then
	echo "$stderr_of_call" >&2
	echo "Make sure that the script is installed on the remediated system." >&2
	echo "See output of the 'dnf provides update-crypto-policies' command" >&2
	echo "to see what package to (re)install" >&2

	false  # end with an error code
elif test "$rc" != 0; then
	echo "Error invoking the update-crypto-policies script: $stderr_of_call" >&2
	false  # end with an error code
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_system_crypto_policy # promote to variable
  set_fact:
    var_system_crypto_policy: !!str FIPS:OSPP
  tags:
    - always

- name: Configure System Cryptography Policy
  lineinfile:
    path: /etc/crypto-policies/config
    regexp: ^(?!#)(\S+)$
    line: '{{ var_system_crypto_policy }}'
    create: true
  tags:
    - CCE-80935-0
    - NIST-800-53-AC-17(2)
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-MA-4(6)
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_crypto_policy
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Verify that Crypto Policy is Set (runtime)
  command: /usr/bin/update-crypto-policies --set {{ var_system_crypto_policy }}
  tags:
    - CCE-80935-0
    - NIST-800-53-AC-17(2)
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-MA-4(6)
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_crypto_policy
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy

Rule   Configure session renegotiation for SSH client   [ref]

The RekeyLimit parameter specifies how often the session key is renegotiated, both in terms of amount of data that may be transmitted and the time elapsed. To decrease the default limits, put line RekeyLimit 1G 1h to file /etc/ssh/ssh_config.d/02-rekey-limit.conf. Make sure that there is no other RekeyLimit configuration preceding the include directive in the main config file /etc/ssh/ssh_config. Check also other files in /etc/ssh/ssh_config.d directory. Files are processed according to lexicographical order of file names. Make sure that there is no file processed before 02-rekey-limit.conf containing definition of RekeyLimit.

Rationale:

By decreasing the limit based on the amount of data and enabling time-based limit, effects of potential attacks against encryption keys are limited.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_ssh_client_rekey_limit
Identifiers and References

Identifiers:  CCE-82880-6

References:  FCS_SSHS_EXT.1




var_ssh_client_rekey_limit_size="1G"

var_ssh_client_rekey_limit_time="1h"



main_config="/etc/ssh/ssh_config"
include_directory="/etc/ssh/ssh_config.d"

if grep -q '^[\s]*RekeyLimit.*$' "$main_config"; then
  sed -i '/^[\s]*RekeyLimit.*/d' "$main_config"
fi

for file in "$include_directory"/*.conf; do
  if grep -q '^[\s]*RekeyLimit.*$' "$file"; then
    sed -i '/^[\s]*RekeyLimit.*/d' "$file"
  fi
done

if [ -e "/etc/ssh/ssh_config.d/02-rekey-limit.conf" ] ; then
    LC_ALL=C sed -i "/^\s*RekeyLimit\s\+/d" "/etc/ssh/ssh_config.d/02-rekey-limit.conf"
else
    touch "/etc/ssh/ssh_config.d/02-rekey-limit.conf"
fi
cp "/etc/ssh/ssh_config.d/02-rekey-limit.conf" "/etc/ssh/ssh_config.d/02-rekey-limit.conf.bak"
# Insert at the end of the file
printf '%s\n' "RekeyLimit $var_ssh_client_rekey_limit_size $var_ssh_client_rekey_limit_time" >> "/etc/ssh/ssh_config.d/02-rekey-limit.conf"
# Clean up after ourselves.
rm "/etc/ssh/ssh_config.d/02-rekey-limit.conf.bak"


Complexity:low
Disruption:low
Strategy:configure
- name: XCCDF Value var_ssh_client_rekey_limit_size # promote to variable
  set_fact:
    var_ssh_client_rekey_limit_size: !!str 1G
  tags:
    - always
- name: XCCDF Value var_ssh_client_rekey_limit_time # promote to variable
  set_fact:
    var_ssh_client_rekey_limit_time: !!str 1h
  tags:
    - always

- name: Ensure RekeyLimit is not configured in /etc/ssh/ssh_config
  lineinfile:
    path: /etc/ssh/ssh_config
    create: false
    regexp: ^\s*RekeyLimit.*$
    state: absent
  tags:
    - CCE-82880-6
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - ssh_client_rekey_limit

- name: Collect all include config files for ssh client which configure RekeyLimit
  find:
    paths: /etc/ssh/ssh_config.d/
    contains: ^[\s]*RekeyLimit.*$
    patterns: '*.config'
  register: ssh_config_include_files
  tags:
    - CCE-82880-6
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - ssh_client_rekey_limit

- name: Remove all occurences of RekeyLimit configuration from include config files
    of ssh client
  lineinfile:
    path: '{{ item }}'
    regexp: ^[\s]*RekeyLimit.*$
    state: absent
  loop: '{{ ssh_config_include_files.files }}'
  tags:
    - CCE-82880-6
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - ssh_client_rekey_limit

- name: Ensure that rekey limit is set to {{ var_ssh_client_rekey_limit_size }} {{
    var_ssh_client_rekey_limit_time }} in /etc/ssh/ssh_config.d/02-rekey-limit.conf
  lineinfile:
    path: /etc/ssh/ssh_config.d/02-rekey-limit.conf
    create: true
    regexp: ^\s*RekeyLimit.*$
    line: RekeyLimit {{ var_ssh_client_rekey_limit_size }} {{ var_ssh_client_rekey_limit_time
      }}
    state: present
  tags:
    - CCE-82880-6
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - ssh_client_rekey_limit

Rule   Configure Kerberos to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. Kerberos is supported by crypto policy, but it's configuration may be set up to ignore it. To check that Crypto Policies settings for Kerberos are configured correctly, examine that there is a symlink at /etc/krb5.conf.d/crypto-policies targeting /etc/cypto-policies/back-ends/krb5.config. If the symlink exists, kerberos is configured to use the system-wide crypto policy settings.

Rationale:

Overriding the system crypto policy makes the behavior of Kerberos violate expectations, and makes system configuration more fragmented.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_kerberos_crypto_policy
Identifiers and References

Identifiers:  CCE-80936-8

References:  SC-13, SC-12(2), SC-12(3), SRG-OS-000120-GPOS-00061



Complexity:low
Disruption:low
Reboot:true
Strategy:configure

rm -f /etc/krb5.conf.d/crypto-policies
ln -s /etc/crypto-policies/back-ends/krb5.config /etc/krb5.conf.d/crypto-policies


Complexity:low
Disruption:low
Reboot:true
Strategy:configure
- name: Configure Kerberos to use System Crypto Policy
  file:
    src: /etc/crypto-policies/back-ends/krb5.config
    path: /etc/krb5.conf.d/crypto-policies
    state: link
  tags:
    - CCE-80936-8
    - NIST-800-53-SC-12(2)
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SC-13
    - configure_kerberos_crypto_policy
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required

Rule   OpenSSL uses strong entropy source   [ref]

By default, OpenSSL doesn't always use a SP800-90A compliant random number generator. A way to configure OpenSSL to always use a strong source is to setup a wrapper that defines a shell function that shadows the actual openssl binary, and that ensures that the -rand /dev/random option is added to every openssl invocation. To do so, place the following shell snippet exactly as-is to /etc/profile.d/openssl-rand.sh:

# provide a default -rand /dev/random option to openssl commands that
# support it

# written inefficiently for maximum shell compatibility
openssl()
(
  openssl_bin=/usr/bin/openssl

  case "$*" in
    # if user specified -rand, honor it
    *\ -rand\ *|*\ -help*) exec $openssl_bin "$@" ;;
  esac

  cmds=`$openssl_bin list -digest-commands -cipher-commands | tr '\n' ' '`
  for i in `$openssl_bin list -commands`; do
    if $openssl_bin list -options "$i" | grep -q '^rand '; then
      cmds=" $i $cmds"
    fi
  done

  case "$cmds" in
    *\ "$1"\ *)
      cmd="$1"; shift
      exec $openssl_bin "$cmd" -rand /dev/random "$@" ;;
  esac

  exec $openssl_bin "$@"
)

Warning:  This setting can cause problems on computers without the hardware random generator, because insufficient entropy blocks the program until enough entropy is available.
Rationale:

This rule ensures that openssl invocations always uses SP800-90A compliant random number generator as a default behavior.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_openssl_use_strong_entropy
Identifiers and References

Identifiers:  CCE-82721-2

References:  FIA_AFL.1, SRG-OS-000480-GPOS-00227




cat > /etc/profile.d/openssl-rand.sh <<- 'EOM'
# provide a default -rand /dev/random option to openssl commands that
# support it

# written inefficiently for maximum shell compatibility
openssl()
(
  openssl_bin=/usr/bin/openssl

  case "$*" in
    # if user specified -rand, honor it
    *\ -rand\ *|*\ -help*) exec $openssl_bin "$@" ;;
  esac

  cmds=`$openssl_bin list -digest-commands -cipher-commands | tr '\n' ' '`
  for i in `$openssl_bin list -commands`; do
    if $openssl_bin list -options "$i" | grep -q '^rand '; then
      cmds=" $i $cmds"
    fi
  done

  case "$cmds" in
    *\ "$1"\ *)
      cmd="$1"; shift
      exec $openssl_bin "$cmd" -rand /dev/random "$@" ;;
  esac

  exec $openssl_bin "$@"
)
EOM


Complexity:low
Disruption:low
Strategy:restrict
- name: Put a file with shell wrapper to configure OpenSSL to always use strong entropy
  copy:
    dest: /etc/profile.d/openssl-rand.sh
    content: |
      # provide a default -rand /dev/random option to openssl commands that
      # support it

      # written inefficiently for maximum shell compatibility
      openssl()
      (
        openssl_bin=/usr/bin/openssl

        case "$*" in
          # if user specified -rand, honor it
          *\ -rand\ *|*\ -help*) exec $openssl_bin "$@" ;;
        esac

        cmds=`$openssl_bin list -digest-commands -cipher-commands | tr '\n' ' '`
        for i in `$openssl_bin list -commands`; do
          if $openssl_bin list -options "$i" | grep -q '^rand '; then
            cmds=" $i $cmds"
          fi
        done

        case "$cmds" in
          *\ "$1"\ *)
            cmd="$1"; shift
            exec $openssl_bin "$cmd" -rand /dev/random "$@" ;;
        esac

        exec $openssl_bin "$@"
      )
  tags:
    - CCE-82721-2
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - openssl_use_strong_entropy
    - restrict_strategy
Group   System Tooling / Utilities   Group contains 17 rules

[ref]   The following checks evaluate the system for recommended base packages -- both for installation and removal.

Rule   Install openscap-scanner Package   [ref]

The openscap-scanner package can be installed with the following command:

$ sudo yum install openscap-scanner

Rationale:

openscap-scanner contains the oscap command line tool. This tool is a configuration and vulnerability scanner, capable of performing compliance checking using SCAP content.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_openscap-scanner_installed
Identifiers and References

Identifiers:  CCE-82220-5

References:  SRG-OS-000480-GPOS-00227, SRG-OS-000191-GPOS-00080



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "openscap-scanner" ; then
    yum install -y "openscap-scanner"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure openscap-scanner is installed
  package:
    name: openscap-scanner
    state: present
  tags:
    - CCE-82220-5
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_openscap-scanner_installed


Complexity:low
Disruption:low
Strategy:enable
include install_openscap-scanner

class install_openscap-scanner {
  package { 'openscap-scanner':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=openscap-scanner

Rule   Install scap-security-guide Package   [ref]

The scap-security-guide package can be installed with the following command:

$ sudo yum install scap-security-guide

Rationale:

The scap-security-guide package provides a guide for configuration of the system from the final system's security point of view. The guidance is specified in the Security Content Automation Protocol (SCAP) format and constitutes a catalog of practical hardening advice, linked to government requirements where applicable. The SCAP Security Guide project bridges the gap between generalized policy requirements and specific implementation guidelines. A system administrator can use the oscap CLI tool from the openscap-scanner package, or the SCAP Workbench GUI tool from the scap-workbench package, to verify that the system conforms to provided guidelines. Refer to the scap-security-guide(8) manual page for futher information.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_scap-security-guide_installed
Identifiers and References

Identifiers:  CCE-82949-9

References:  SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "scap-security-guide" ; then
    yum install -y "scap-security-guide"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure scap-security-guide is installed
  package:
    name: scap-security-guide
    state: present
  tags:
    - CCE-82949-9
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_scap-security-guide_installed


Complexity:low
Disruption:low
Strategy:enable
include install_scap-security-guide

class install_scap-security-guide {
  package { 'scap-security-guide':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=scap-security-guide

Rule   Install rng-tools Package   [ref]

The rng-tools package can be installed with the following command:

$ sudo yum install rng-tools

Rationale:

rng-tools provides hardware random number generator tools, such as those used in the formation of x509/PKI certificates.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_rng-tools_installed
Identifiers and References

Identifiers:  CCE-82968-9

References:  SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "rng-tools" ; then
    yum install -y "rng-tools"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure rng-tools is installed
  package:
    name: rng-tools
    state: present
  tags:
    - CCE-82968-9
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_rng-tools_installed


Complexity:low
Disruption:low
Strategy:enable
include install_rng-tools

class install_rng-tools {
  package { 'rng-tools':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=rng-tools

Rule   Install dnf-plugin-subscription-manager Package   [ref]

The dnf-plugin-subscription-manager package can be installed with the following command:

$ sudo yum install dnf-plugin-subscription-manager

Rationale:

This package provides plugins to interact with repositories and subscriptions from the Red Hat entitlement platform; contains subscription-manager and product-id plugins.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_dnf-plugin-subscription-manager_installed
Identifiers and References

Identifiers:  CCE-82315-3

References:  FPT_TUD_EXT.1, FPT_TUD_EXT.2, SRG-OS-000366-GPOS-00153



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "dnf-plugin-subscription-manager" ; then
    yum install -y "dnf-plugin-subscription-manager"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure dnf-plugin-subscription-manager is installed
  package:
    name: dnf-plugin-subscription-manager
    state: present
  tags:
    - CCE-82315-3
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_dnf-plugin-subscription-manager_installed


Complexity:low
Disruption:low
Strategy:enable
include install_dnf-plugin-subscription-manager

class install_dnf-plugin-subscription-manager {
  package { 'dnf-plugin-subscription-manager':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=dnf-plugin-subscription-manager

Rule   Install subscription-manager Package   [ref]

The subscription-manager package can be installed with the following command:

$ sudo yum install subscription-manager

Rationale:

Red Hat Subscription Manager is a local service which tracks installed products and subscriptions on a local system to help manage subscription assignments. It communicates with the backend subscription service (the Customer Portal or an on-premise server such as Subscription Asset Manager) and works with content management tools such as yum.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_subscription-manager_installed
Identifiers and References

Identifiers:  CCE-82316-1

References:  FPT_TUD_EXT.1, FPT_TUD_EXT.2, SRG-OS-000366-GPOS-00153



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "subscription-manager" ; then
    yum install -y "subscription-manager"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure subscription-manager is installed
  package:
    name: subscription-manager
    state: present
  tags:
    - CCE-82316-1
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_subscription-manager_installed


Complexity:low
Disruption:low
Strategy:enable
include install_subscription-manager

class install_subscription-manager {
  package { 'subscription-manager':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=subscription-manager

Rule   Uninstall abrt-addon-python Package   [ref]

The abrt-addon-python package can be removed with the following command:

$ sudo yum erase abrt-addon-python

Rationale:

abrt-addon-python contains python hook and python analyzer plugin for handling uncaught exceptions in python programs.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-addon-python_removed
Identifiers and References

Identifiers:  CCE-82923-4

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-addon-python
#	   from the system, and may remove any packages
#	   that depend on abrt-addon-python. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-addon-python" ; then
    yum remove -y "abrt-addon-python"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-addon-python is removed
  package:
    name: abrt-addon-python
    state: absent
  tags:
    - CCE-82923-4
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-addon-python_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-addon-python

class remove_abrt-addon-python {
  package { 'abrt-addon-python':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-addon-python

Rule   Uninstall gssproxy Package   [ref]

The gssproxy package can be removed with the following command:

$ sudo yum erase gssproxy

Rationale:

gssproxy is a proxy for GSS API credential handling.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_gssproxy_removed
Identifiers and References

Identifiers:  CCE-82943-2

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove gssproxy
#	   from the system, and may remove any packages
#	   that depend on gssproxy. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "gssproxy" ; then
    yum remove -y "gssproxy"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure gssproxy is removed
  package:
    name: gssproxy
    state: absent
  tags:
    - CCE-82943-2
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_gssproxy_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_gssproxy

class remove_gssproxy {
  package { 'gssproxy':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=gssproxy

Rule   Uninstall pigz Package   [ref]

The pigz package can be removed with the following command:

$ sudo yum erase pigz

Rationale:

Binaries shipped in pigz package in Red Hat Enterprise Linux 8 have not been compiled using recommended compiler flags. The binaries are compiled without sufficient stack protection and its address space layout randomization (ASLR) is weak.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_pigz_removed
Identifiers and References

Identifiers:  CCE-82397-1

References:  SRG-OS-000433-GPOS-00192



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove pigz
#	   from the system, and may remove any packages
#	   that depend on pigz. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "pigz" ; then
    yum remove -y "pigz"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure pigz is removed
  package:
    name: pigz
    state: absent
  tags:
    - CCE-82397-1
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_pigz_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_pigz

class remove_pigz {
  package { 'pigz':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=pigz

Rule   Uninstall iprutils Package   [ref]

The iprutils package can be removed with the following command:

$ sudo yum erase iprutils

Rationale:

iprutils provides a suite of utlilities to manage and configure SCSI devices supported by the ipr SCSI storage device driver.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_iprutils_removed
Identifiers and References

Identifiers:  CCE-82946-5

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove iprutils
#	   from the system, and may remove any packages
#	   that depend on iprutils. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "iprutils" ; then
    yum remove -y "iprutils"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure iprutils is removed
  package:
    name: iprutils
    state: absent
  tags:
    - CCE-82946-5
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_iprutils_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_iprutils

class remove_iprutils {
  package { 'iprutils':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=iprutils

Rule   Uninstall abrt-addon-ccpp Package   [ref]

The abrt-addon-ccpp package can be removed with the following command:

$ sudo yum erase abrt-addon-ccpp

Rationale:

abrt-addon-ccpp contains hooks for C/C++ crashed programs and abrt's C/C++ analyzer plugin.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-addon-ccpp_removed
Identifiers and References

Identifiers:  CCE-82919-2

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-addon-ccpp
#	   from the system, and may remove any packages
#	   that depend on abrt-addon-ccpp. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-addon-ccpp" ; then
    yum remove -y "abrt-addon-ccpp"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-addon-ccpp is removed
  package:
    name: abrt-addon-ccpp
    state: absent
  tags:
    - CCE-82919-2
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-addon-ccpp_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-addon-ccpp

class remove_abrt-addon-ccpp {
  package { 'abrt-addon-ccpp':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-addon-ccpp

Rule   Uninstall abrt-plugin-sosreport Package   [ref]

The abrt-plugin-sosreport package can be removed with the following command:

$ sudo yum erase abrt-plugin-sosreport

Rationale:

abrt-plugin-sosreport provides a plugin to include an sosreport in an ABRT report.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-plugin-sosreport_removed
Identifiers and References

Identifiers:  CCE-82910-1

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-plugin-sosreport
#	   from the system, and may remove any packages
#	   that depend on abrt-plugin-sosreport. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-plugin-sosreport" ; then
    yum remove -y "abrt-plugin-sosreport"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-plugin-sosreport is removed
  package:
    name: abrt-plugin-sosreport
    state: absent
  tags:
    - CCE-82910-1
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-plugin-sosreport_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-plugin-sosreport

class remove_abrt-plugin-sosreport {
  package { 'abrt-plugin-sosreport':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-plugin-sosreport

Rule   Uninstall abrt-plugin-logger Package   [ref]

The abrt-plugin-logger package can be removed with the following command:

$ sudo yum erase abrt-plugin-logger

Rationale:

abrt-plugin-logger is an ABRT plugin which writes a report to a specified file.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-plugin-logger_removed
Identifiers and References

Identifiers:  CCE-82913-5

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-plugin-logger
#	   from the system, and may remove any packages
#	   that depend on abrt-plugin-logger. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-plugin-logger" ; then
    yum remove -y "abrt-plugin-logger"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-plugin-logger is removed
  package:
    name: abrt-plugin-logger
    state: absent
  tags:
    - CCE-82913-5
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-plugin-logger_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-plugin-logger

class remove_abrt-plugin-logger {
  package { 'abrt-plugin-logger':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-plugin-logger

Rule   Uninstall krb5-workstation Package   [ref]

The krb5-workstation package can be removed with the following command:

$ sudo yum erase krb5-workstation

Rationale:

Kerberos is a network authentication system. The krb5-workstation package contains the basic Kerberos programs (kinit, klist, kdestroy, kpasswd). Currently, Kerberos does not utilize FIPS 140-2 cryptography and is not permitted on Government networks, nor is it permitted in many regulatory environments such as HIPAA.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_krb5-workstation_removed
Identifiers and References

Identifiers:  CCE-82931-7

References:  SRG-OS-000095-GPOS-00049, SRG-OS-000120-GPOS-00061



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove krb5-workstation
#	   from the system, and may remove any packages
#	   that depend on krb5-workstation. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "krb5-workstation" ; then
    yum remove -y "krb5-workstation"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure krb5-workstation is removed
  package:
    name: krb5-workstation
    state: absent
  tags:
    - CCE-82931-7
    - disable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_krb5-workstation_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_krb5-workstation

class remove_krb5-workstation {
  package { 'krb5-workstation':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=krb5-workstation

Rule   Uninstall abrt-cli Package   [ref]

The abrt-cli package can be removed with the following command:

$ sudo yum erase abrt-cli

Rationale:

abrt-cli contains a command line client for controlling abrt daemon over sockets.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-cli_removed
Identifiers and References

Identifiers:  CCE-82907-7

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-cli
#	   from the system, and may remove any packages
#	   that depend on abrt-cli. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-cli" ; then
    yum remove -y "abrt-cli"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-cli is removed
  package:
    name: abrt-cli
    state: absent
  tags:
    - CCE-82907-7
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-cli_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-cli

class remove_abrt-cli {
  package { 'abrt-cli':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-cli

Rule   Uninstall tuned Package   [ref]

The tuned package can be removed with the following command:

$ sudo yum erase tuned

Rationale:

tuned contains a daemon that tunes the system settings dynamically. It does so by monitoring the usage of several system components periodically. Based on that information, components will then be put into lower or higher power savings modes to adapt to the current usage.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_tuned_removed
Identifiers and References

Identifiers:  CCE-82904-4

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove tuned
#	   from the system, and may remove any packages
#	   that depend on tuned. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "tuned" ; then
    yum remove -y "tuned"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure tuned is removed
  package:
    name: tuned
    state: absent
  tags:
    - CCE-82904-4
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_tuned_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_tuned

class remove_tuned {
  package { 'tuned':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=tuned

Rule   Uninstall abrt-plugin-rhtsupport Package   [ref]

The abrt-plugin-rhtsupport package can be removed with the following command:

$ sudo yum erase abrt-plugin-rhtsupport

Rationale:

abrt-plugin-rhtsupport is a ABRT plugin to report bugs into the Red Hat Support system.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-plugin-rhtsupport_removed
Identifiers and References

Identifiers:  CCE-82916-8

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-plugin-rhtsupport
#	   from the system, and may remove any packages
#	   that depend on abrt-plugin-rhtsupport. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-plugin-rhtsupport" ; then
    yum remove -y "abrt-plugin-rhtsupport"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-plugin-rhtsupport is removed
  package:
    name: abrt-plugin-rhtsupport
    state: absent
  tags:
    - CCE-82916-8
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-plugin-rhtsupport_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-plugin-rhtsupport

class remove_abrt-plugin-rhtsupport {
  package { 'abrt-plugin-rhtsupport':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-plugin-rhtsupport

Rule   Uninstall abrt-addon-kerneloops Package   [ref]

The abrt-addon-kerneloops package can be removed with the following command:

$ sudo yum erase abrt-addon-kerneloops

Rationale:

abrt-addon-kerneloops contains plugins for collecting kernel crash information and reporter plugin which sends this information to a specified server, usually to kerneloops.org.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt-addon-kerneloops_removed
Identifiers and References

Identifiers:  CCE-82926-7

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt-addon-kerneloops
#	   from the system, and may remove any packages
#	   that depend on abrt-addon-kerneloops. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt-addon-kerneloops" ; then
    yum remove -y "abrt-addon-kerneloops"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt-addon-kerneloops is removed
  package:
    name: abrt-addon-kerneloops
    state: absent
  tags:
    - CCE-82926-7
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_abrt-addon-kerneloops_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt-addon-kerneloops

class remove_abrt-addon-kerneloops {
  package { 'abrt-addon-kerneloops':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt-addon-kerneloops
Group   Updating Software   Group contains 8 rules

[ref]   The yum command line tool is used to install and update software packages. The system also provides a graphical software update tool in the System menu, in the Administration submenu, called Software Update.

Red Hat Enterprise Linux 8 systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using yum or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.

Rule   Install dnf-automatic Package   [ref]

The dnf-automatic package can be installed with the following command:

$ sudo yum install dnf-automatic

Rationale:

dnf-automatic is an alternative command line interface (CLI) to dnf upgrade suitable for automatic, regular execution.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_dnf-automatic_installed
Identifiers and References

Identifiers:  CCE-82985-3

References:  SRG-OS-000191-GPOS-00080



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "dnf-automatic" ; then
    yum install -y "dnf-automatic"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure dnf-automatic is installed
  package:
    name: dnf-automatic
    state: present
  tags:
    - CCE-82985-3
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_dnf-automatic_installed


Complexity:low
Disruption:low
Strategy:enable
include install_dnf-automatic

class install_dnf-automatic {
  package { 'dnf-automatic':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=dnf-automatic

Rule   Ensure gpgcheck Enabled for Local Packages   [ref]

yum should be configured to verify the signature(s) of local packages prior to installation. To configure yum to verify signatures of local packages, set the localpkg_gpgcheck to 1 in /etc/yum.conf.

Rationale:

Changes to any software components can have significant effects to the overall security of the operating system. This requirement ensures the software has not been tampered and has been provided by a trusted vendor.

Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_local_packages
Identifiers and References

Identifiers:  CCE-80791-7

References:  NT28(R15), 11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-11(a), CM-11(b), CM-6(a), CM-5(3), SA-12, SA-12(10), PR.IP-1, FAU_GEN.1.1.c, SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650



# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/yum.conf' '^localpkg_gpgcheck' '1' 'CCE-80791-7'


Complexity:low
Disruption:medium
- name: Check existence of yum on Fedora
  stat:
    path: /etc/yum.conf
  register: yum_config_file
  check_mode: false
  when: ansible_distribution == "Fedora"
  tags:
    - CCE-80791-7
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check Enabled for Local Packages (Yum)
  ini_file:
    dest: /etc/yum.conf
    section: main
    option: localpkg_gpgcheck
    value: 1
    create: true
  when: (ansible_distribution == "RedHat" or ansible_distribution == "CentOS" or ansible_distribution
    == "Scientific" or yum_config_file.stat.exists)
  tags:
    - CCE-80791-7
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check Enabled for Local Packages (DNF)
  ini_file:
    dest: /etc/dnf/dnf.conf
    section: main
    option: localpkg_gpgcheck
    value: 1
    create: true
  when: ansible_distribution == "Fedora"
  tags:
    - CCE-80791-7
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

Rule   Enable dnf-automatic Timer   [ref]

The dnf-automatic timer can be enabled with the following command:

$ sudo systemctl enable dnf-automatic.timer

Rationale:

The dnf-automatic is an alternative command line interface (CLI) to dnf upgrade with specific facilities to make it suitable to be executed automatically and regularly from systemd timers, cron jobs and similar. The tool is controlled by dnf-automatic.timer SystemD timer.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_timer_dnf-automatic_enabled
Identifiers and References

Identifiers:  CCE-82360-9

References:  SI-2(5), CM-6(a), SI-2(c), FMT_SMF_EXT.1, SRG-OS-000191-GPOS-00080



Complexity:low
Disruption:low
Strategy:enable

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" start 'dnf-automatic.timer'
"$SYSTEMCTL_EXEC" enable 'dnf-automatic.timer'


Complexity:low
Disruption:low
Strategy:enable
- name: Enable timer dnf-automatic
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable timer dnf-automatic
      systemd:
        name: dnf-automatic.timer
        enabled: 'yes'
        state: started
      when:
        - '"dnf-automatic" in ansible_facts.packages'
  tags:
    - CCE-82360-9
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-2(5)
    - NIST-800-53-SI-2(c)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - timer_dnf-automatic_enabled

Rule   Configure dnf-automatic to Install Available Updates Automatically   [ref]

To ensure that the packages comprising the available updates will be automatically installed by dnf-automatic, set apply_updates to yes under [commands] section in /etc/dnf/automatic.conf.

Rationale:

Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise. The automated installation of updates ensures that recent security patches are applied in a timely manner.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_dnf-automatic_apply_updates
Identifiers and References

Identifiers:  CCE-82494-6

References:  SI-2(5), CM-6(a), SI-2(c), FMT_SMF_EXT.1, SRG-OS-000191-GPOS-00080




CONF="/etc/dnf/automatic.conf"
APPLY_UPDATES_REGEX="[[:space:]]*\[commands]([^\n\[]*\n+)+?[[:space:]]*apply_updates"
COMMANDS_REGEX="[[:space:]]*\[commands]"

# Try find [commands] and apply_updates in automatic.conf, if it exists, set
# to yes, if it isn't here, add it, if [commands] doesn't exist, add it there
if grep -qzosP $APPLY_UPDATES_REGEX $CONF; then
    sed -i "s/apply_updates[^(\n)]*/apply_updates = yes/" $CONF
elif grep -qs $COMMANDS_REGEX $CONF; then
    sed -i "/$COMMANDS_REGEX/a apply_updates = yes" $CONF
else
    mkdir -p /etc/dnf
    echo -e "[commands]\napply_updates = yes" >> $CONF
fi


Complexity:low
Disruption:medium
- name: Configure dnf-automatic to Install Available Updates Automatically
  ini_file:
    dest: /etc/dnf/automatic.conf
    section: commands
    option: apply_updates
    value: 'yes'
    create: true
  tags:
    - CCE-82494-6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-2(5)
    - NIST-800-53-SI-2(c)
    - dnf-automatic_apply_updates
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
    - unknown_strategy

Rule   Configure dnf-automatic to Install Only Security Updates   [ref]

To configure dnf-automatic to install only security updates automatically, set upgrade_type to security under [commands] section in /etc/dnf/automatic.conf.

Rationale:

By default, dnf-automatic installs all available updates. Reducing the amount of updated packages only to updates that were issued as a part of a security advisory increases the system stability.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_dnf-automatic_security_updates_only
Identifiers and References

Identifiers:  CCE-82267-6

References:  SI-2(5), CM-6(a), SI-2(c), FMT_SMF_EXT.1, SRG-OS-000191-GPOS-00080




CONF="/etc/dnf/automatic.conf"
APPLY_UPDATES_REGEX="[[:space:]]*\[commands]([^\n\[]*\n+)+?[[:space:]]*upgrade_type"
COMMANDS_REGEX="[[:space:]]*\[commands]"

# Try find [commands] and upgrade_type in automatic.conf, if it exists, set
# it to security, if it isn't here, add it, if [commands] doesn't exist,
# add it there
if grep -qzosP $APPLY_UPDATES_REGEX $CONF; then
    sed -i "s/upgrade_type[^(\n)]*/upgrade_type = security/" $CONF
elif grep -qs $COMMANDS_REGEX $CONF; then
    sed -i "/$COMMANDS_REGEX/a upgrade_type = security" $CONF
else
    mkdir -p /etc/dnf
    echo -e "[commands]\nupgrade_type = security" >> $CONF
fi


Complexity:low
Disruption:medium
- name: Configure dnf-automatic to Install Only Security Updates
  ini_file:
    dest: /etc/dnf/automatic.conf
    section: commands
    option: upgrade_type
    value: security
    create: true
  tags:
    - CCE-82267-6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-2(5)
    - NIST-800-53-SI-2(c)
    - dnf-automatic_security_updates_only
    - low_complexity
    - low_severity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

Rule   Ensure gpgcheck Enabled In Main yum Configuration   [ref]

The gpgcheck option controls whether RPM packages' signatures are always checked prior to installation. To configure yum to check package signatures before installing them, ensure the following line appears in /etc/yum.conf in the [main] section:

gpgcheck=1

Rationale:

Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA).

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated
Identifiers and References

Identifiers:  CCE-80790-9

References:  NT28(R15), 1.2.4, 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FAU_GEN.1.1.c, Req-6.2, SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650



# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append "/etc/yum.conf" '^gpgcheck' '1' 'CCE-80790-9'


Complexity:low
Disruption:medium
- name: Check existence of yum on Fedora
  stat:
    path: /etc/yum.conf
  register: yum_config_file
  check_mode: false
  when: ansible_distribution == "Fedora"
  tags:
    - CCE-80790-9
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check is globally activated (yum)
  ini_file:
    dest: /etc/yum.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when: (ansible_distribution == "RedHat" or ansible_distribution == "CentOS" or ansible_distribution
    == "Scientific" or yum_config_file.stat.exists)
  tags:
    - CCE-80790-9
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check is globally activated (dnf)
  ini_file:
    dest: /etc/dnf/dnf.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when: ansible_distribution == "Fedora"
  tags:
    - CCE-80790-9
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

Rule   Ensure gpgcheck Enabled for All yum Package Repositories   [ref]

To ensure signature checking is not disabled for any repos, remove any lines from files in /etc/yum.repos.d of the form:

gpgcheck=0

Rationale:

Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA)."

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_never_disabled
Identifiers and References

Identifiers:  CCE-80792-5

References:  NT28(R15), 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FAU_GEN.1.1.c, Req-6.2, SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650



sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/yum.repos.d/*


Complexity:low
Disruption:medium
Strategy:enable
- name: Grep for yum repo section names
  shell: grep -HEr '^\[.+\]' -r /etc/yum.repos.d/
  register: repo_grep_results
  ignore_errors: true
  changed_when: false
  tags:
    - CCE-80792-5
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - enable_strategy
    - ensure_gpgcheck_never_disabled
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed

- name: Set gpgcheck=1 for each yum repo
  ini_file:
    path: '{{ item[0] }}'
    section: '{{ item[1] }}'
    option: gpgcheck
    value: '1'
    no_extra_spaces: true
  loop: '{{ repo_grep_results.stdout | regex_findall( ''(.+\.repo):\[(.+)\]\n?'' )
    }}'
  tags:
    - CCE-80792-5
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - enable_strategy
    - ensure_gpgcheck_never_disabled
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed

Rule   Ensure Red Hat GPG Key Installed   [ref]

To ensure the system can cryptographically verify base software packages come from Red Hat (and to connect to the Red Hat Network to receive them), the Red Hat GPG key must properly be installed. To install the Red Hat GPG key, run:

$ sudo subscription-manager register
If the system is not connected to the Internet or an RHN Satellite, then install the Red Hat GPG key from trusted media such as the Red Hat installation CD-ROM or DVD. Assuming the disc is mounted in /media/cdrom, use the following command as the root user to import it into the keyring:
$ sudo rpm --import /media/cdrom/RPM-GPG-KEY
Alternatively, the key may be pre-loaded during the RHEL installation. In such cases, the key can be installed by running the following command:
sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Rationale:

Changes to software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. The Red Hat GPG key is necessary to cryptographically verify packages are from Red Hat.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_redhat_gpgkey_installed
Identifiers and References

Identifiers:  CCE-80795-8

References:  NT28(R15), 1.2.3, 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), PR.DS-6, PR.DS-8, PR.IP-1, FAU_GEN.1.1.c, Req-6.2, SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650



# The two fingerprints below are retrieved from https://access.redhat.com/security/team/key
readonly REDHAT_RELEASE_FINGERPRINT="567E347AD0044ADE55BA8A5F199E2F91FD431D51"
readonly REDHAT_AUXILIARY_FINGERPRINT="6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792"

# Location of the key we would like to import (once it's integrity verified)
readonly REDHAT_RELEASE_KEY="/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"

RPM_GPG_DIR_PERMS=$(stat -c %a "$(dirname "$REDHAT_RELEASE_KEY")")

# Verify /etc/pki/rpm-gpg directory permissions are safe
if [ "${RPM_GPG_DIR_PERMS}" -le "755" ]
then
  # If they are safe, try to obtain fingerprints from the key file
  # (to ensure there won't be e.g. CRC error).

  readarray -t GPG_OUT < <(gpg --show-keys --with-fingerprint --with-colons "$REDHAT_RELEASE_KEY" | grep -A1 "^pub" | grep "^fpr" | cut -d ":" -f 10)

  GPG_RESULT=$?
  # No CRC error, safe to proceed
  if [ "${GPG_RESULT}" -eq "0" ]
  then
    echo "${GPG_OUT[*]}" | grep -vE "${REDHAT_RELEASE_FINGERPRINT}|${REDHAT_AUXILIARY_FINGERPRINT}" || {
      # If $REDHAT_RELEASE_KEY file doesn't contain any keys with unknown fingerprint, import it
      rpm --import "${REDHAT_RELEASE_KEY}"
    }
  fi
fi


Complexity:medium
Disruption:medium
Strategy:restrict
- name: Read permission of GPG key directory
  stat:
    path: /etc/pki/rpm-gpg/
  register: gpg_key_directory_permission
  check_mode: false
  tags:
    - CCE-80795-8
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Read signatures in GPG key
  command: gpg --show-keys --with-fingerprint --with-colons "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"
  args:
    warn: false
  changed_when: false
  register: gpg_fingerprints
  check_mode: false
  tags:
    - CCE-80795-8
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Set Fact - Installed GPG Fingerprints
  set_fact:
    gpg_installed_fingerprints: |-
      {{ gpg_fingerprints.stdout | regex_findall('^pub.*
      (?:^fpr[:]*)([0-9A-Fa-f]*)', '\1') | list }}
  tags:
    - CCE-80795-8
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Set Fact - Valid fingerprints
  set_fact:
    gpg_valid_fingerprints: ("567E347AD0044ADE55BA8A5F199E2F91FD431D51" "6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792")
  tags:
    - CCE-80795-8
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Import RedHat GPG key
  rpm_key:
    state: present
    key: /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
  when:
    - gpg_key_directory_permission.stat.mode <= '0755'
    - (gpg_installed_fingerprints | difference(gpg_valid_fingerprints)) | length ==
      0
    - gpg_installed_fingerprints | length > 0
    - ansible_distribution == "RedHat"
  tags:
    - CCE-80795-8
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
Group   Sudo   Group contains 1 rule

[ref]   Sudo, which stands for "su 'do'", provides the ability to delegate authority to certain users, groups of users, or system administrators. When configured for system users and/or groups, Sudo can allow a user or group to execute privileged commands that normally only root is allowed to execute.

For more information on Sudo and addition Sudo configuration options, see https://www.sudo.ws.

Rule   Install sudo Package   [ref]

The sudo package can be installed with the following command:

$ sudo yum install sudo

Rationale:

sudo is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_sudo_installed
Identifiers and References

Identifiers:  CCE-82214-8

References:  1.3.1, CM-6(a), SRG-OS-000324-GPOS-00125



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "sudo" ; then
    yum install -y "sudo"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure sudo is installed
  package:
    name: sudo
    state: present
  tags:
    - CCE-82214-8
    - NIST-800-53-CM-6(a)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_sudo_installed


Complexity:low
Disruption:low
Strategy:enable
include install_sudo

class install_sudo {
  package { 'sudo':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=sudo
Group   Disk Partitioning   Group contains 4 rules

[ref]   To ensure separation and protection of data, there are top-level system directories which should be placed on their own physical partition or logical volume. The installer's default partitioning scheme creates separate logical volumes for /, /boot, and swap.

  • If starting with any of the default layouts, check the box to \"Review and modify partitioning.\" This allows for the easy creation of additional logical volumes inside the volume group already created, though it may require making /'s logical volume smaller to create space. In general, using logical volumes is preferable to using partitions because they can be more easily adjusted later.
  • If creating a custom layout, create the partitions mentioned in the previous paragraph (which the installer will require anyway), as well as separate ones described in the following sections.
If a system has already been installed, and the default partitioning scheme was used, it is possible but nontrivial to modify it to create separate logical volumes for the directories listed above. The Logical Volume Manager (LVM) makes this possible. See the LVM HOWTO at http://tldp.org/HOWTO/LVM-HOWTO/ for more detailed information on LVM.

Rule   Ensure /home Located On Separate Partition   [ref]

If user home directories will be stored locally, create a separate partition for /home at installation time (or migrate it later using LVM). If /home will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.

Rationale:

Ensuring that /home is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_home
Identifiers and References

Identifiers:  CCE-81044-0

References:  NT28(R12), 1.1.13, 12, 15, 8, APO13.01, DSS05.02, CCI-000366, CCI-001208, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:high
Strategy:enable

part /home

Rule   Ensure /var/log Located On Separate Partition   [ref]

System logs are stored in the /var/log directory. Ensure that it has its own partition or logical volume at installation time, or migrate it using LVM.

Rationale:

Placing /var/log in its own partition enables better separation between log files and other files in /var/.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_var_log
Identifiers and References

Identifiers:  CCE-80853-5

References:  NT28(R12), NT28(R47), 1.1.11, 1, 12, 14, 15, 16, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, DSS05.02, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), AU-4, SC-5(2), PR.PT-1, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:high
Strategy:enable

part /var/log

Rule   Ensure /var Located On Separate Partition   [ref]

The /var directory is used by daemons and other system services to store frequently-changing data. Ensure that /var has its own partition or logical volume at installation time, or migrate it using LVM.

Rationale:

Ensuring that /var is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the /var directory to contain world-writable directories installed by other software packages.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_var
Identifiers and References

Identifiers:  CCE-80852-7

References:  NT28(R12), 1.1.6, 12, 15, 8, APO13.01, DSS05.02, CCI-000366, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, SRG-OS-000341-VMM-001220



Complexity:low
Disruption:high
Strategy:enable

part /var

Rule   Ensure /var/log/audit Located On Separate Partition   [ref]

Audit logs are stored in the /var/log/audit directory. Ensure that it has its own partition or logical volume at installation time, or migrate it later using LVM. Make absolutely certain that it is large enough to store all audit logs that will be created by the auditing daemon.

Rationale:

Placing /var/log/audit in its own partition enables better separation between audit files and other files, and helps ensure that auditing cannot be halted due to the partition running out of space.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_var_log_audit
Identifiers and References

Identifiers:  CCE-80854-3

References:  1.1.12, 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.02, DSS05.04, DSS05.07, MEA02.01, CCI-000366, CCI-001849, 164.312(a)(2)(ii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.2, SR 7.6, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.17.2.1, CM-6(a), AU-4, SC-5(2), PR.DS-4, PR.PT-1, PR.PT-4, SRG-OS-000341-GPOS-00132, SRG-OS-000480-GPOS-00227, SRG-OS-000341-VMM-001220



Complexity:low
Disruption:high
Strategy:enable

part /var/log/audit
Group   GRUB2 bootloader configuration   Group contains 2 rules

[ref]   During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows for the selection of different kernels - possibly on different partitions or media. The default Red Hat Enterprise Linux 8 boot loader for x86 systems is called GRUB2. Options it can pass to the kernel include single-user mode, which provides root access without any authentication, and the ability to disable SELinux. To prevent local users from modifying the boot parameters and endangering security, protect the boot loader configuration with a password and ensure its configuration file's permissions are set properly.

Rule   Enable Kernel Page-Table Isolation (KPTI)   [ref]

To enable Kernel page-table isolation, add the argument pti=on to the default GRUB 2 command line for the Linux operating system in /etc/default/grub, in the manner below:

GRUB_CMDLINE_LINUX="pti=on"

Warning:  The GRUB 2 configuration file, grub.cfg, is automatically updated each time a new kernel is installed. Note that any changes to /etc/default/grub require rebuilding the grub.cfg file. To update the GRUB 2 configuration file manually, use the
grub2-mkconfig -o
command as follows:
  • On BIOS-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
  • On UEFI-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Rationale:

Kernel page-table isolation is a kernel feature that mitigates the Meltdown security vulnerability and hardens the kernel against attempts to bypass kernel address space layout randomization (KASLR).

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_pti_argument
Identifiers and References

Identifiers:  CCE-82194-2

References:  SI-16, SRG-OS-000433-GPOS-00193





# Correct grub2 kernelopts value using grub2-editenv
if ! grub2-editenv - list | grep -qE '^kernelopts=(.*\s)?pti=on(\s.*)?$'; then
  grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) pti=on"
fi


Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: get current kernel parameters
  command: /usr/bin/grub2-editenv - list
  register: kernelopts
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82194-2
    - NIST-800-53-SI-16
    - grub2_pti_argument
    - high_severity
    - low_disruption
    - medium_complexity
    - reboot_required
    - restrict_strategy

- name: Update the bootloader menu
  command: /usr/bin/grub2-editenv - set "{{ item }} pti=on"
  with_items: '{{ kernelopts.stdout_lines | select(''match'', ''^kernelopts.*'') |
    list }}'
  when:
    - kernelopts.stdout_lines is defined
    - kernelopts.stdout_lines | length > 0
    - kernelopts.stdout | regex_search('^kernelopts=(?:.*\s)?pti=on(?:\s.*)?$', multiline=True)
      is none
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82194-2
    - NIST-800-53-SI-16
    - grub2_pti_argument
    - high_severity
    - low_disruption
    - medium_complexity
    - reboot_required
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  kernelArguments:
    - pti=on

Rule   Set the UEFI Boot Loader Password   [ref]

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the pasword by running the following command:

$ grub2-setpassword
When prompted, enter the password that was selected.

Once the superuser password has been added, update the grub.cfg file by running:
grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg

Warning:  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Rationale:

Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_uefi_password
Identifiers and References

Identifiers:  CCE-80829-5

References:  NT28(R17), 1.4.2, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_AFL.1, SRG-OS-000080-GPOS-00048

Group   SELinux   Group contains 4 rules

[ref]   SELinux is a feature of the Linux kernel which can be used to guard against misconfigured or compromised programs. SELinux enforces the idea that programs should be limited in what files they can access and what actions they can take.

The default SELinux policy, as configured on Red Hat Enterprise Linux 8, has been sufficiently developed and debugged that it should be usable on almost any system with minimal configuration and a small amount of system administrator training. This policy prevents system services - including most of the common network-visible services such as mail servers, FTP servers, and DNS servers - from accessing files which those services have no valid reason to access. This action alone prevents a huge amount of possible damage from network attacks against services, from trojaned software, and so forth.

This guide recommends that SELinux be enabled using the default (targeted) policy on every Red Hat Enterprise Linux 8 system, unless that system has unusual requirements which make a stronger policy appropriate.

Rule   Install policycoreutils Package   [ref]

The policycoreutils package can be installed with the following command:

$ sudo yum install policycoreutils

Rationale:

Security-enhanced Linux is a feature of the Linux kernel and a number of utilities with enhanced security functionality designed to add mandatory access controls to Linux. The Security-enhanced Linux kernel contains new architectural components originally developed to improve security of the Flask operating system. These architectural components provide general support for the enforcement of many kinds of mandatory access control policies, including those based on the concepts of Type Enforcement, Role-based Access Control, and Multi-level Security. policycoreutils contains the policy core utilities that are required for basic operation of an SELinux-enabled system. These utilities include load_policy to load SELinux policies, setfiles to label filesystems, newrole to switch roles, and run_init to run /etc/init.d scripts in the proper context.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_policycoreutils_installed
Identifiers and References

Identifiers:  CCE-82976-2

References:  SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "policycoreutils" ; then
    yum install -y "policycoreutils"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure policycoreutils is installed
  package:
    name: policycoreutils
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82976-2
    - enable_strategy
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - package_policycoreutils_installed


Complexity:low
Disruption:low
Strategy:enable
include install_policycoreutils

class install_policycoreutils {
  package { 'policycoreutils':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=policycoreutils

Rule   Install policycoreutils-python-utils package   [ref]

The policycoreutils-python-utils package can be installed with the following command:

$ sudo yum install policycoreutils-python-utils

Rationale:

This package is required to operate and manage an SELinux environment and its policies. It provides utilities such as semanage, audit2allow, audit2why, chcat and sandbox.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_policycoreutils-python-utils_installed
Identifiers and References

Identifiers:  CCE-82724-6

References:  SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "policycoreutils-python-utils" ; then
    yum install -y "policycoreutils-python-utils"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure policycoreutils-python-utils is installed
  package:
    name: policycoreutils-python-utils
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82724-6
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_policycoreutils-python-utils_installed


Complexity:low
Disruption:low
Strategy:enable
include install_policycoreutils-python-utils

class install_policycoreutils-python-utils {
  package { 'policycoreutils-python-utils':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=policycoreutils-python-utils

Rule   Ensure SELinux State is Enforcing   [ref]

The SELinux state should be set to enforcing at system boot time. In the file /etc/selinux/config, add or correct the following line to configure the system to boot into enforcing mode:

SELINUX=enforcing

Rationale:

Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_selinux_state
Identifiers and References

Identifiers:  CCE-80869-1

References:  NT28(R4), 1.7.1.4, 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-002165, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000445-GPOS-00199, SRG-OS-000445-VMM-001780



Complexity:low
Disruption:low
Reboot:true
Strategy:restrict

var_selinux_state="enforcing"

if [ -e "/etc/selinux/config" ] ; then
    LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
else
    touch "/etc/selinux/config"
fi
cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUX=$var_selinux_state" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"

fixfiles onboot
fixfiles -f relabel


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_selinux_state # promote to variable
  set_fact:
    var_selinux_state: !!str enforcing
  tags:
    - always

- name: Ensure SELinux State is Enforcing
  block:

    - name: Deduplicate values from /etc/selinux/config
      lineinfile:
        path: /etc/selinux/config
        create: false
        regexp: ^SELINUX=
        state: absent

    - name: Insert correct line to /etc/selinux/config
      lineinfile:
        path: /etc/selinux/config
        create: true
        line: SELINUX={{ var_selinux_state }}
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80869-1
    - NIST-800-171-3.1.2
    - NIST-800-171-3.7.2
    - NIST-800-53-AC-3
    - NIST-800-53-AC-3(3)(a)
    - NIST-800-53-AU-9
    - NIST-800-53-SC-7(21)
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - selinux_state

Rule   Configure SELinux Policy   [ref]

The SELinux targeted policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in /etc/selinux/config:

SELINUXTYPE=targeted
Other policies, such as mls, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.

Rationale:

Setting the SELinux policy to targeted or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services.

Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in permissive mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to targeted.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_selinux_policytype
Identifiers and References

Identifiers:  CCE-80868-3

References:  NT28(R66), 1.7.1.3, 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000445-GPOS-00199, SRG-OS-000445-VMM-001780



Complexity:low
Disruption:low
Reboot:true
Strategy:restrict

var_selinux_policy_name="targeted"

if [ -e "/etc/selinux/config" ] ; then
    LC_ALL=C sed -i "/^SELINUXTYPE=/Id" "/etc/selinux/config"
else
    touch "/etc/selinux/config"
fi
cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUXTYPE=$var_selinux_policy_name" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: XCCDF Value var_selinux_policy_name # promote to variable
  set_fact:
    var_selinux_policy_name: !!str targeted
  tags:
    - always

- name: Configure SELinux Policy
  block:

    - name: Deduplicate values from /etc/selinux/config
      lineinfile:
        path: /etc/selinux/config
        create: false
        regexp: ^SELINUXTYPE=
        state: absent

    - name: Insert correct line to /etc/selinux/config
      lineinfile:
        path: /etc/selinux/config
        create: true
        line: SELINUXTYPE={{ var_selinux_policy_name }}
        state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80868-3
    - NIST-800-171-3.1.2
    - NIST-800-171-3.7.2
    - NIST-800-53-AC-3
    - NIST-800-53-AC-3(3)(a)
    - NIST-800-53-AU-9
    - NIST-800-53-SC-7(21)
    - high_severity
    - low_complexity
    - low_disruption
    - reboot_required
    - restrict_strategy
    - selinux_policytype
Group   File Permissions and Masks   Group contains 7 groups and 40 rules

[ref]   Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access.

Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn.

The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Red Hat Enterprise Linux 8 installations:

$ mount -t xfs | awk '{print $3}'
For any systems that use a different local filesystem type, modify this command as appropriate.

Group   Verify Permissions on Important Files and Directories   Group contains 2 rules

[ref]   Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.

Group   Restrict Programs from Dangerous Execution Patterns   Group contains 3 groups and 16 rules

[ref]   The recommendations in this section are designed to ensure that the system's features to protect against potentially dangerous program execution are activated. These protections are applied at the system initialization or kernel level, and defend against certain types of badly-configured or compromised programs.

Group   Enable ExecShield   Group contains 1 rule

[ref]   ExecShield describes kernel features that provide protection against exploitation of memory corruption errors such as buffer overflows. These features include random placement of the stack and other memory regions, prevention of execution in memory that should only hold data, and special handling of text buffers. These protections are enabled by default on 32-bit systems and controlled through sysctl variables kernel.exec-shield and kernel.randomize_va_space. On the latest 64-bit systems, kernel.exec-shield cannot be enabled or disabled with sysctl.

Rule   Restrict Exposed Kernel Pointer Addresses Access   [ref]

To set the runtime status of the kernel.kptr_restrict kernel parameter, run the following command:

$ sudo sysctl -w kernel.kptr_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.kptr_restrict = 1

Rationale:

Exposing kernel pointers (through procfs or seq_printf()) exposes kernel writeable structures that can contain functions pointers. If a write vulnereability occurs in the kernel allowing a write access to any of this structure, the kernel can be compromise. This option disallow any program withtout the CAP_SYSLOG capability from getting the kernel pointers addresses, replacing them with 0.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_kptr_restrict
Identifiers and References

Identifiers:  CCE-80915-2

References:  NT28(R23), SC-30, SC-30(2), SC-30(5), CM-6(a), SRG-OS-000132-GPOS-00067



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.kptr_restrict
#
/sbin/sysctl -q -n -w kernel.kptr_restrict="1"

#
# If kernel.kptr_restrict present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.kptr_restrict = 1" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.kptr_restrict' "1" 'CCE-80915-2'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.kptr_restrict is set to 1
  sysctl:
    name: kernel.kptr_restrict
    value: '1'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80915-2
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-30
    - NIST-800-53-SC-30(2)
    - NIST-800-53-SC-30(5)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_kernel_kptr_restrict


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.kptr_restrict%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_kptr_restrict.conf
Group   Disable Core Dumps   Group contains 4 rules

[ref]   A core dump file is the memory image of an executable program when it was terminated by the operating system due to errant behavior. In most cases, only software developers legitimately need to access these files. The core dump files may also contain sensitive information, or unnecessarily occupy large amounts of disk space.

Once a hard limit is set in /etc/security/limits.conf, or to a file within the /etc/security/limits.d/ directory, a user cannot increase that limit within his or her own session. If access to core dumps is required, consider restricting them to only certain users or groups. See the limits.conf man page for more information.

The core dumps of setuid programs are further protected. The sysctl variable fs.suid_dumpable controls whether the kernel allows core dumps from these programs at all. The default value of 0 is recommended.

Rule   Disable acquiring, saving, and processing core dumps   [ref]

The systemd-coredump.socket unit is a socket activation of the systemd-coredump@.service which processes core dumps. By masking the unit, core dump processing is disabled.

Rationale:

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_service_systemd-coredump_disabled
Identifiers and References

Identifiers:  CCE-82881-4

References:  FMT_SMF_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:disable


SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" stop 'systemd-coredump.service'
"$SYSTEMCTL_EXEC" disable 'systemd-coredump.service'
"$SYSTEMCTL_EXEC" mask 'systemd-coredump.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" list-unit-files | grep -q '^systemd-coredump.socket'; then
    "$SYSTEMCTL_EXEC" stop 'systemd-coredump.socket'
    "$SYSTEMCTL_EXEC" disable 'systemd-coredump.socket'
    "$SYSTEMCTL_EXEC" mask 'systemd-coredump.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'systemd-coredump.service' || true


Complexity:low
Disruption:low
Strategy:disable
- name: Disable service systemd-coredump
  block:

    - name: Gather the service facts
      service_facts: null

    - name: Disable service systemd-coredump
      systemd:
        name: systemd-coredump.service
        enabled: 'no'
        state: stopped
        masked: 'yes'
      when: '"systemd-coredump.service" in ansible_facts.services'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82881-4
    - disable_strategy
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - service_systemd-coredump_disabled
    - unknown_severity

- name: Unit Socket Exists - systemd-coredump.socket
  command: systemctl list-unit-files systemd-coredump.socket
  args:
    warn: false
  register: socket_file_exists
  changed_when: false
  ignore_errors: true
  check_mode: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82881-4
    - disable_strategy
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - service_systemd-coredump_disabled
    - unknown_severity

- name: Disable socket systemd-coredump
  systemd:
    name: systemd-coredump.socket
    enabled: 'no'
    state: stopped
    masked: 'yes'
  when:
    - '"systemd-coredump.socket" in socket_file_exists.stdout_lines[1]'
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82881-4
    - disable_strategy
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - service_systemd-coredump_disabled
    - unknown_severity


Complexity:low
Disruption:low
Strategy:enable
include disable_systemd-coredump

class disable_systemd-coredump {
  service {'systemd-coredump':
    enable => false,
    ensure => 'stopped',
  }
}


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    systemd:
      units:
      - name: systemd-coredump.service
        enabled: false
        mask: true
      - name: systemd-coredump.socket
        enabled: false
        mask: true


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    systemd:
      units:
      - name: systemd-coredump.service
        enabled: false
        mask: true
      - name: systemd-coredump.socket
        enabled: false
        mask: true

Rule   Disable Core Dumps for All Users   [ref]

To disable core dumps for all users, add the following line to /etc/security/limits.conf, or to a file within the /etc/security/limits.d/ directory:

*     hard   core    0

Rationale:

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_disable_users_coredumps
Identifiers and References

Identifiers:  CCE-81038-2

References:  1.6.1, 1, 12, 13, 15, 16, 2, 7, 8, APO13.01, BAI04.04, DSS01.03, DSS03.05, DSS05.07, SR 6.2, SR 7.1, SR 7.2, A.12.1.3, A.17.2.1, DE.CM-1, PR.DS-4, SRG-OS-000480-GPOS-00227



SECURITY_LIMITS_FILE="/etc/security/limits.conf"

if grep -qE '\*\s+hard\s+core' $SECURITY_LIMITS_FILE; then
        sed -ri 's/(hard\s+core\s+)[[:digit:]]+/\1 0/' $SECURITY_LIMITS_FILE
else
        echo "*     hard   core    0" >> $SECURITY_LIMITS_FILE
fi


Complexity:low
Disruption:low
Strategy:restrict
- name: disable core dumps with limits
  lineinfile:
    dest: /etc/security/limits.conf
    regexp: ^[^#].*core
    line: '*        hard       core      0'
    create: true
  tags:
    - CCE-81038-2
    - disable_users_coredumps
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%2A%20%20%20%20%20hard%20%20%20core%20%20%20%200
        filesystem: root
        mode: 0644
        path: /etc/security/limits.d/75-disable_users_coredumps.conf

Rule   Disable storing core dump   [ref]

The Storage option in [Coredump] section of /etc/systemd/coredump.conf can be set to none to disable storing core dumps permanently.

Warning:  If the /etc/systemd/coredump.conf file does not already contain the [Coredump] section, the value will not be configured correctly.
Rationale:

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended, however there may be overriding operational requirements to enable advanced debuging. Permitting temporary enablement of core dumps during such situations should be reviewed through local needs and policy.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_coredump_disable_storage
Identifiers and References

Identifiers:  CCE-82252-8

References:  1.6.1, FMT_SMF_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/systemd/coredump.conf" ] ; then
    LC_ALL=C sed -i "/^\s*Storage\s*=\s*/Id" "/etc/systemd/coredump.conf"
else
    touch "/etc/systemd/coredump.conf"
fi
cp "/etc/systemd/coredump.conf" "/etc/systemd/coredump.conf.bak"
# Insert at the end of the file
printf '%s\n' "Storage=none" >> "/etc/systemd/coredump.conf"
# Clean up after ourselves.
rm "/etc/systemd/coredump.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable storing core dump
  block:

    - name: Deduplicate values from /etc/systemd/coredump.conf
      lineinfile:
        path: /etc/systemd/coredump.conf
        create: false
        regexp: ^\s*Storage\s*=\s*
        state: absent

    - name: Insert correct line to /etc/systemd/coredump.conf
      lineinfile:
        path: /etc/systemd/coredump.conf
        create: false
        line: Storage=none
        state: present
  tags:
    - CCE-82252-8
    - coredump_disable_storage
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%20%20This%20file%20is%20part%20of%20systemd.%0A%23%0A%23%20%20systemd%20is%20free%20software%3B%20you%20can%20redistribute%20it%20and/or%20modify%20it%0A%23%20%20under%20the%20terms%20of%20the%20GNU%20Lesser%20General%20Public%20License%20as%20published%20by%0A%23%20%20the%20Free%20Software%20Foundation%3B%20either%20version%202.1%20of%20the%20License%2C%20or%0A%23%20%20%28at%20your%20option%29%20any%20later%20version.%0A%23%0A%23%20Entries%20in%20this%20file%20show%20the%20compile%20time%20defaults.%0A%23%20You%20can%20change%20settings%20by%20editing%20this%20file.%0A%23%20Defaults%20can%20be%20restored%20by%20simply%20deleting%20this%20file.%0A%23%0A%23%20See%20coredump.conf%285%29%20for%20details.%0A%0A%5BCoredump%5D%0A%23Storage%3Dexternal%0A%23Compress%3Dyes%0A%23ProcessSizeMax%3D2G%0A%23ExternalSizeMax%3D2G%0A%23JournalSizeMax%3D767M%0A%23MaxUse%3D%0A%23KeepFree%3D%0AStorage%3Dnone%0AProcessSizeMax%3D0%0A
        filesystem: root
        mode: 0644
        path: /etc/systemd/coredump.conf

Rule   Disable core dump backtraces   [ref]

The ProcessSizeMax option in [Coredump] section of /etc/systemd/coredump.conf specifies the maximum size in bytes of a core which will be processed. Core dumps exceeding this size may be stored, but the backtrace will not be generated.

Warning:  If the /etc/systemd/coredump.conf file does not already contain the [Coredump] section, the value will not be configured correctly.
Rationale:

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended, however there may be overriding operational requirements to enable advanced debuging. Permitting temporary enablement of core dumps during such situations should be reviewed through local needs and policy.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_coredump_disable_backtraces
Identifiers and References

Identifiers:  CCE-82251-0

References:  1.6.1, FMT_SMF_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/systemd/coredump.conf" ] ; then
    LC_ALL=C sed -i "/^\s*ProcessSizeMax\s*=\s*/Id" "/etc/systemd/coredump.conf"
else
    touch "/etc/systemd/coredump.conf"
fi
cp "/etc/systemd/coredump.conf" "/etc/systemd/coredump.conf.bak"
# Insert at the end of the file
printf '%s\n' "ProcessSizeMax=0" >> "/etc/systemd/coredump.conf"
# Clean up after ourselves.
rm "/etc/systemd/coredump.conf.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable core dump backtraces
  block:

    - name: Deduplicate values from /etc/systemd/coredump.conf
      lineinfile:
        path: /etc/systemd/coredump.conf
        create: false
        regexp: ^\s*ProcessSizeMax\s*=\s*
        state: absent

    - name: Insert correct line to /etc/systemd/coredump.conf
      lineinfile:
        path: /etc/systemd/coredump.conf
        create: false
        line: ProcessSizeMax=0
        state: present
  tags:
    - CCE-82251-0
    - coredump_disable_backtraces
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%20%20This%20file%20is%20part%20of%20systemd.%0A%23%0A%23%20%20systemd%20is%20free%20software%3B%20you%20can%20redistribute%20it%20and/or%20modify%20it%0A%23%20%20under%20the%20terms%20of%20the%20GNU%20Lesser%20General%20Public%20License%20as%20published%20by%0A%23%20%20the%20Free%20Software%20Foundation%3B%20either%20version%202.1%20of%20the%20License%2C%20or%0A%23%20%20%28at%20your%20option%29%20any%20later%20version.%0A%23%0A%23%20Entries%20in%20this%20file%20show%20the%20compile%20time%20defaults.%0A%23%20You%20can%20change%20settings%20by%20editing%20this%20file.%0A%23%20Defaults%20can%20be%20restored%20by%20simply%20deleting%20this%20file.%0A%23%0A%23%20See%20coredump.conf%285%29%20for%20details.%0A%0A%5BCoredump%5D%0A%23Storage%3Dexternal%0A%23Compress%3Dyes%0A%23ProcessSizeMax%3D2G%0A%23ExternalSizeMax%3D2G%0A%23JournalSizeMax%3D767M%0A%23MaxUse%3D%0A%23KeepFree%3D%0AStorage%3Dnone%0AProcessSizeMax%3D0%0A
        filesystem: root
        mode: 0644
        path: /etc/systemd/coredump.conf
Group   Memory Poisoning   Group contains 2 rules

[ref]   Memory Poisoning consists of writing a special value to uninitialized or freed memory. Poisoning can be used as a mechanism to prevent leak of information and detection of corrupted memory.

Rule   Enable page allocator poisoning   [ref]

To enable poisoning of free pages, add the argument page_poison=1 to the default GRUB 2 command line for the Linux operating system in /etc/default/grub, in the manner below:

GRUB_CMDLINE_LINUX="page_poison=1"

Warning:  The GRUB 2 configuration file, grub.cfg, is automatically updated each time a new kernel is installed. Note that any changes to /etc/default/grub require rebuilding the grub.cfg file. To update the GRUB 2 configuration file manually, use the
grub2-mkconfig -o
command as follows:
  • On BIOS-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
  • On UEFI-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Rationale:

Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_page_poison_argument
Identifiers and References

Identifiers:  CCE-80944-2

References:  CM-6(a), SRG-OS-000480-GPOS-00227





# Correct grub2 kernelopts value using grub2-editenv
if ! grub2-editenv - list | grep -qE '^kernelopts=(.*\s)?page_poison=1(\s.*)?$'; then
  grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) page_poison=1"
fi


Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: get current kernel parameters
  command: /usr/bin/grub2-editenv - list
  register: kernelopts
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80944-2
    - NIST-800-53-CM-6(a)
    - grub2_page_poison_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Update the bootloader menu
  command: /usr/bin/grub2-editenv - set "{{ item }} page_poison=1"
  with_items: '{{ kernelopts.stdout_lines | select(''match'', ''^kernelopts.*'') |
    list }}'
  when:
    - kernelopts.stdout_lines is defined
    - kernelopts.stdout_lines | length > 0
    - kernelopts.stdout | regex_search('^kernelopts=(?:.*\s)?page_poison=1(?:\s.*)?$',
      multiline=True) is none
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80944-2
    - NIST-800-53-CM-6(a)
    - grub2_page_poison_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  kernelArguments:
    - page_poison=1

Rule   Enable SLUB/SLAB allocator poisoning   [ref]

To enable poisoning of SLUB/SLAB objects, add the argument slub_debug=P to the default GRUB 2 command line for the Linux operating system in /etc/default/grub, in the manner below:

GRUB_CMDLINE_LINUX="slub_debug=P"

Warning:  The GRUB 2 configuration file, grub.cfg, is automatically updated each time a new kernel is installed. Note that any changes to /etc/default/grub require rebuilding the grub.cfg file. To update the GRUB 2 configuration file manually, use the
grub2-mkconfig -o
command as follows:
  • On BIOS-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
  • On UEFI-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Rationale:

Poisoning writes an arbitrary value to freed objects, so any modification or reference to that object after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_slub_debug_argument
Identifiers and References

Identifiers:  CCE-80945-9

References:  CM-6(a), SRG-OS-000433-GPOS-00192





# Correct grub2 kernelopts value using grub2-editenv
if ! grub2-editenv - list | grep -qE '^kernelopts=(.*\s)?slub_debug=P(\s.*)?$'; then
  grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) slub_debug=P"
fi


Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: get current kernel parameters
  command: /usr/bin/grub2-editenv - list
  register: kernelopts
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80945-9
    - NIST-800-53-CM-6(a)
    - grub2_slub_debug_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Update the bootloader menu
  command: /usr/bin/grub2-editenv - set "{{ item }} slub_debug=P"
  with_items: '{{ kernelopts.stdout_lines | select(''match'', ''^kernelopts.*'') |
    list }}'
  when:
    - kernelopts.stdout_lines is defined
    - kernelopts.stdout_lines | length > 0
    - kernelopts.stdout | regex_search('^kernelopts=(?:.*\s)?slub_debug=P(?:\s.*)?$',
      multiline=True) is none
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80945-9
    - NIST-800-53-CM-6(a)
    - grub2_slub_debug_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  kernelArguments:
    - slub_debug=P

Rule   Disable the use of user namespaces   [ref]

To set the runtime status of the user.max_user_namespaces kernel parameter, run the following command:

$ sudo sysctl -w user.max_user_namespaces=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
user.max_user_namespaces = 0
When containers are deployed on the machine, the value should be set to large non-zero value.

Warning:  This configuration baseline was created to deploy the base operating system for general purpose workloads. When the operating system is configured for certain purposes, such as to host Linux Containers, it is expected that user.max_user_namespaces will be enabled.
Rationale:

User namespaces are used primarily for Linux containers. The value 0 disallows the use of user namespaces.

Severity: 
info
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_user_max_user_namespaces
Identifiers and References

Identifiers:  CCE-82211-4

References:  SC-39, CM-6(a), FMT_SMF_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for user.max_user_namespaces
#
/sbin/sysctl -q -n -w user.max_user_namespaces="0"

#
# If user.max_user_namespaces present in /etc/sysctl.conf, change value to "0"
#	else, add "user.max_user_namespaces = 0" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^user.max_user_namespaces' "0" 'CCE-82211-4'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl user.max_user_namespaces is set to 0
  sysctl:
    name: user.max_user_namespaces
    value: '0'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82211-4
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-39
    - disable_strategy
    - low_complexity
    - low_severity
    - medium_disruption
    - reboot_required
    - sysctl_user_max_user_namespaces


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,user.max_user_namespaces%20%3D%200%0A
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_user_max_user_namespaces.conf

Rule   Disable Access to Network bpf() Syscall From Unprivileged Processes   [ref]

To set the runtime status of the kernel.unprivileged_bpf_disabled kernel parameter, run the following command:

$ sudo sysctl -w kernel.unprivileged_bpf_disabled=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.unprivileged_bpf_disabled = 1

Rationale:

Loading and accessing the packet filters programs and maps using the bpf() syscall has the potential of revealing sensitive information about the kernel state.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_unprivileged_bpf_disabled
Identifiers and References

Identifiers:  CCE-82974-7

References:  FMT_SMF_EXT.1, SRG-OS-000132-GPOS-00067



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.unprivileged_bpf_disabled
#
/sbin/sysctl -q -n -w kernel.unprivileged_bpf_disabled="1"

#
# If kernel.unprivileged_bpf_disabled present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.unprivileged_bpf_disabled = 1" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.unprivileged_bpf_disabled' "1" 'CCE-82974-7'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.unprivileged_bpf_disabled is set to 1
  sysctl:
    name: kernel.unprivileged_bpf_disabled
    value: '1'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82974-7
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_kernel_unprivileged_bpf_disabled


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.unprivileged_bpf_disabled%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_unprivileged_bpf_disabled.conf

Rule   Disallow kernel profiling by unprivileged users   [ref]

To set the runtime status of the kernel.perf_event_paranoid kernel parameter, run the following command:

$ sudo sysctl -w kernel.perf_event_paranoid=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.perf_event_paranoid = 2

Rationale:

Kernel profiling can reveal sensitive information about kernel behaviour.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_perf_event_paranoid
Identifiers and References

Identifiers:  CCE-81054-9

References:  NT28(R23), FMT_SMF_EXT.1, SRG-OS-000132-GPOS-00067



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.perf_event_paranoid
#
/sbin/sysctl -q -n -w kernel.perf_event_paranoid="2"

#
# If kernel.perf_event_paranoid present in /etc/sysctl.conf, change value to "2"
#	else, add "kernel.perf_event_paranoid = 2" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.perf_event_paranoid' "2" 'CCE-81054-9'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.perf_event_paranoid is set to 2
  sysctl:
    name: kernel.perf_event_paranoid
    value: '2'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81054-9
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_kernel_perf_event_paranoid


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.perf_event_paranoid%3D2
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_perf_event_paranoid.conf

Rule   Disable Kernel Image Loading   [ref]

To set the runtime status of the kernel.kexec_load_disabled kernel parameter, run the following command:

$ sudo sysctl -w kernel.kexec_load_disabled=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.kexec_load_disabled = 1

Rationale:

Disabling kexec_load allows greater control of the kernel memory. It makes it impossible to load another kernel image after it has been disabled.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_kexec_load_disabled
Identifiers and References

Identifiers:  CCE-80952-5

References:  SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.kexec_load_disabled
#
/sbin/sysctl -q -n -w kernel.kexec_load_disabled="1"

#
# If kernel.kexec_load_disabled present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.kexec_load_disabled = 1" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.kexec_load_disabled' "1" 'CCE-80952-5'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.kexec_load_disabled is set to 1
  sysctl:
    name: kernel.kexec_load_disabled
    value: '1'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80952-5
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_kernel_kexec_load_disabled


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.kexec_load_disabled%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_kexec_load_disabled.conf

Rule   Disable storing core dumps   [ref]

To set the runtime status of the kernel.core_pattern kernel parameter, run the following command:

$ sudo sysctl -w kernel.core_pattern=|/bin/false
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.core_pattern = |/bin/false

Rationale:

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_core_pattern
Identifiers and References

Identifiers:  CCE-82215-5

References:  FMT_SMF_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.core_pattern
#
/sbin/sysctl -q -n -w kernel.core_pattern="|/bin/false"

#
# If kernel.core_pattern present in /etc/sysctl.conf, change value to "|/bin/false"
#	else, add "kernel.core_pattern = |/bin/false" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.core_pattern' "|/bin/false" 'CCE-82215-5'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.core_pattern is set to |/bin/false
  sysctl:
    name: kernel.core_pattern
    value: '|/bin/false'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82215-5
    - disable_strategy
    - low_complexity
    - medium_disruption
    - reboot_required
    - sysctl_kernel_core_pattern
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.core_pattern%20%3D%20%7C/bin/false%0A
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_core_pattern.conf

Rule   Restrict usage of ptrace to descendant processes   [ref]

To set the runtime status of the kernel.yama.ptrace_scope kernel parameter, run the following command:

$ sudo sysctl -w kernel.yama.ptrace_scope=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.yama.ptrace_scope = 1

Rationale:

Unrestricted usage of ptrace allows compromised binaries to run ptrace on another processes of the user. Like this, the attacker can steal sensitive information from the target processes (e.g. SSH sessions, web browser, ...) without any additional assistance from the user (i.e. without resorting to phishing).

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_yama_ptrace_scope
Identifiers and References

Identifiers:  CCE-80953-3

References:  NT28(R25), SRG-OS-000132-GPOS-00067



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.yama.ptrace_scope
#
/sbin/sysctl -q -n -w kernel.yama.ptrace_scope="1"

#
# If kernel.yama.ptrace_scope present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.yama.ptrace_scope = 1" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.yama.ptrace_scope' "1" 'CCE-80953-3'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.yama.ptrace_scope is set to 1
  sysctl:
    name: kernel.yama.ptrace_scope
    value: '1'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80953-3
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_kernel_yama_ptrace_scope


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.yama.ptrace_scope%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_yama_ptrace_scope.conf

Rule   Restrict Access to Kernel Message Buffer   [ref]

To set the runtime status of the kernel.dmesg_restrict kernel parameter, run the following command:

$ sudo sysctl -w kernel.dmesg_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.dmesg_restrict = 1

Rationale:

Unprivileged access to the kernel syslog can expose sensitive kernel address information.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_dmesg_restrict
Identifiers and References

Identifiers:  CCE-80913-7

References:  NT28(R23), 3.1.5, CCI-001314, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), SI-11(a), SI-11(b), SRG-OS-000132-GPOS-00067



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for kernel.dmesg_restrict
#
/sbin/sysctl -q -n -w kernel.dmesg_restrict="1"

#
# If kernel.dmesg_restrict present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.dmesg_restrict = 1" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^kernel.dmesg_restrict' "1" 'CCE-80913-7'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl kernel.dmesg_restrict is set to 1
  sysctl:
    name: kernel.dmesg_restrict
    value: '1'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80913-7
    - NIST-800-171-3.1.5
    - NIST-800-53-SI-11(a)
    - NIST-800-53-SI-11(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_kernel_dmesg_restrict


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,kernel.dmesg_restrict%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_dmesg_restrict.conf

Rule   Harden the operation of the BPF just-in-time compiler   [ref]

To set the runtime status of the net.core.bpf_jit_harden kernel parameter, run the following command:

$ sudo sysctl -w net.core.bpf_jit_harden=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.core.bpf_jit_harden = 2

Rationale:

When hardened, the extended Berkeley Packet Filter just-in-time compiler will randomize any kernel addresses in the BPF programs and maps, and will not expose the JIT addresses in /proc/kallsyms.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_core_bpf_jit_harden
Identifiers and References

Identifiers:  CCE-82934-1

References:  FMT_SMF_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for net.core.bpf_jit_harden
#
/sbin/sysctl -q -n -w net.core.bpf_jit_harden="2"

#
# If net.core.bpf_jit_harden present in /etc/sysctl.conf, change value to "2"
#	else, add "net.core.bpf_jit_harden = 2" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.core.bpf_jit_harden' "2" 'CCE-82934-1'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl net.core.bpf_jit_harden is set to 2
  sysctl:
    name: net.core.bpf_jit_harden
    value: '2'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82934-1
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_core_bpf_jit_harden

Rule   Disable vsyscalls   [ref]

To disable use of virtual syscalls, add the argument vsyscall=none to the default GRUB 2 command line for the Linux operating system in /etc/default/grub, in the manner below:

GRUB_CMDLINE_LINUX="vsyscall=none"

Warning:  The GRUB 2 configuration file, grub.cfg, is automatically updated each time a new kernel is installed. Note that any changes to /etc/default/grub require rebuilding the grub.cfg file. To update the GRUB 2 configuration file manually, use the
grub2-mkconfig -o
command as follows:
  • On BIOS-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
  • On UEFI-based machines, issue the following command as root:
    ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Rationale:

Virtual Syscalls provide an opportunity of attack for a user who has control of the return instruction pointer.

Severity: 
info
Rule ID:xccdf_org.ssgproject.content_rule_grub2_vsyscall_argument
Identifiers and References

Identifiers:  CCE-80946-7

References:  CM-7(a), SRG-OS-000480-GPOS-00227





# Correct grub2 kernelopts value using grub2-editenv
if ! grub2-editenv - list | grep -qE '^kernelopts=(.*\s)?vsyscall=none(\s.*)?$'; then
  grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) vsyscall=none"
fi


Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: get current kernel parameters
  command: /usr/bin/grub2-editenv - list
  register: kernelopts
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80946-7
    - NIST-800-53-CM-7(a)
    - grub2_vsyscall_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Update the bootloader menu
  command: /usr/bin/grub2-editenv - set "{{ item }} vsyscall=none"
  with_items: '{{ kernelopts.stdout_lines | select(''match'', ''^kernelopts.*'') |
    list }}'
  when:
    - kernelopts.stdout_lines is defined
    - kernelopts.stdout_lines | length > 0
    - kernelopts.stdout | regex_search('^kernelopts=(?:.*\s)?vsyscall=none(?:\s.*)?$',
      multiline=True) is none
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80946-7
    - NIST-800-53-CM-7(a)
    - grub2_vsyscall_argument
    - low_disruption
    - medium_complexity
    - medium_severity
    - reboot_required
    - restrict_strategy
Group   Restrict Partition Mount Options   Group contains 21 rules

[ref]   System partitions can be mounted with certain options that limit what files on those partitions can do. These options are set in the /etc/fstab configuration file, and can be used to make certain types of malicious behavior more difficult.

Rule   Add nosuid Option to /dev/shm   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /dev/shm. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_dev_shm_nosuid
Identifiers and References

Identifiers:  CCE-80839-4

References:  1.1.16, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "no" = 'yes'; then
		assert_mount_point_in_fstab /dev/shm || { echo "Not remediating, because there is no record of /dev/shm in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/dev/shm" "nosuid" "tmpfs" "tmpfs"

	ensure_partition_is_mounted "/dev/shm"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt  '/dev/shm'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80839-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nosuid
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80839-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nosuid
    - no_reboot_needed

- name: Make sure nosuid option is part of the to /dev/shm options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80839-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nosuid
    - no_reboot_needed

- name: Ensure /dev/shm is mounted with nosuid option
  mount:
    path: /dev/shm
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80839-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nosuid
    - no_reboot_needed

Rule   Add nodev Option to /home   [ref]

The nodev mount option can be used to prevent device files from being created in /home. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /home.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_home_nodev
Identifiers and References

Identifiers:  CCE-81048-1

References:  NT28(R12), 1.1.14, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /home || { echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/home" "nodev" "" ""

	ensure_partition_is_mounted "/home"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/home'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81048-1
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_home_nodev
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81048-1
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_home_nodev
    - no_reboot_needed
    - unknown_severity

- name: Make sure nodev option is part of the to /home options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81048-1
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_home_nodev
    - no_reboot_needed
    - unknown_severity

- name: Ensure /home is mounted with nodev option
  mount:
    path: /home
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81048-1
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_home_nodev
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /home --mountoptions="nodev"

Rule   Add nodev Option to /boot   [ref]

The nodev mount option can be used to prevent device files from being created in /boot. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /boot.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_boot_nodev
Identifiers and References

Identifiers:  CCE-82941-6

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /boot || { echo "Not remediating, because there is no record of /boot in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/boot" "nodev" "" ""

	ensure_partition_is_mounted "/boot"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/boot'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82941-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nodev
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82941-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nodev
    - no_reboot_needed

- name: Make sure nodev option is part of the to /boot options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82941-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nodev
    - no_reboot_needed

- name: Ensure /boot is mounted with nodev option
  mount:
    path: /boot
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82941-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nodev
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /boot --mountoptions="nodev"

Rule   Add nodev Option to Non-Root Local Partitions   [ref]

The nodev mount option prevents files from being interpreted as character or block devices. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of any non-root local partitions.

Rationale:

The nodev mount option prevents files from being interpreted as character or block devices. The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails, for which it is not advised to set nodev on these filesystems.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_nodev_nonroot_local_partitions
Identifiers and References

Identifiers:  CCE-82069-6

References:  1.1.11, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-3, SRG-OS-000368-GPOS-00154

Rule   Add noexec Option to /dev/shm   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /dev/shm. It can be dangerous to allow the execution of binaries from world-writable temporary storage directories such as /dev/shm. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

Rationale:

Allowing users to execute binaries from world-writable directories such as /dev/shm can expose the system to potential compromise.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_dev_shm_noexec
Identifiers and References

Identifiers:  CCE-80838-6

References:  1.1.17, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "no" = 'yes'; then
		assert_mount_point_in_fstab /dev/shm || { echo "Not remediating, because there is no record of /dev/shm in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/dev/shm" "noexec" "tmpfs" "tmpfs"

	ensure_partition_is_mounted "/dev/shm"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt  '/dev/shm'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80838-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_noexec
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80838-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_noexec
    - no_reboot_needed

- name: Make sure noexec option is part of the to /dev/shm options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
    - mount_info is defined and "noexec" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80838-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_noexec
    - no_reboot_needed

- name: Ensure /dev/shm is mounted with noexec option
  mount:
    path: /dev/shm
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80838-6
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_noexec
    - no_reboot_needed

Rule   Add nosuid Option to /home   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /home. The SUID and SGID permissions should not be required in these user data directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /home.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from user home directory partitions.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_home_nosuid
Identifiers and References

Identifiers:  CCE-81050-7

References:  NT28(R12), 1.1.3, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /home || { echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/home" "nosuid" "" ""

	ensure_partition_is_mounted "/home"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/home'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81050-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_home_nosuid
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81050-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_home_nosuid
    - no_reboot_needed

- name: Make sure nosuid option is part of the to /home options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81050-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_home_nosuid
    - no_reboot_needed

- name: Ensure /home is mounted with nosuid option
  mount:
    path: /home
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81050-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_home_nosuid
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /home --mountoptions="nosuid"

Rule   Add nosuid Option to /var/tmp   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /var/tmp. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nosuid
Identifiers and References

Identifiers:  CCE-82154-6

References:  NT28(R12), 1.1.9, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/tmp || { echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/tmp" "nosuid" "" ""

	ensure_partition_is_mounted "/var/tmp"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82154-6
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nosuid
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82154-6
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nosuid
    - no_reboot_needed
    - unknown_severity

- name: Make sure nosuid option is part of the to /var/tmp options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82154-6
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nosuid
    - no_reboot_needed
    - unknown_severity

- name: Ensure /var/tmp is mounted with nosuid option
  mount:
    path: /var/tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82154-6
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nosuid
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /var/tmp --mountoptions="nosuid"

Rule   Add nosuid Option to /tmp   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /tmp. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_tmp_nosuid
Identifiers and References

Identifiers:  CCE-82140-5

References:  NT28(R12), 1.1.4, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /tmp || { echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/tmp" "nosuid" "" ""

	ensure_partition_is_mounted "/tmp"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82140-5
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nosuid
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82140-5
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nosuid
    - no_reboot_needed
    - unknown_severity

- name: Make sure nosuid option is part of the to /tmp options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82140-5
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nosuid
    - no_reboot_needed
    - unknown_severity

- name: Ensure /tmp is mounted with nosuid option
  mount:
    path: /tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82140-5
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nosuid
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /tmp --mountoptions="nosuid"

Rule   Add nodev Option to /var/log   [ref]

The nodev mount option can be used to prevent device files from being created in /var/log. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_nodev
Identifiers and References

Identifiers:  CCE-82077-9

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/log || { echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/log" "nodev" "" ""

	ensure_partition_is_mounted "/var/log"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/log'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82077-9
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nodev
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82077-9
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nodev
    - no_reboot_needed

- name: Make sure nodev option is part of the to /var/log options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82077-9
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nodev
    - no_reboot_needed

- name: Ensure /var/log is mounted with nodev option
  mount:
    path: /var/log
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82077-9
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nodev
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var/log --mountoptions="nodev"

Rule   Add noexec Option to /var/log   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /var/log. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.

Rationale:

Allowing users to execute binaries from directories containing log files such as /var/log should never be necessary in normal operation and can expose the system to potential compromise.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_noexec
Identifiers and References

Identifiers:  CCE-82008-4

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/log || { echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/log" "noexec" "" ""

	ensure_partition_is_mounted "/var/log"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/log'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82008-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_noexec
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82008-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_noexec
    - no_reboot_needed

- name: Make sure noexec option is part of the to /var/log options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
    - mount_info is defined and "noexec" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82008-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_noexec
    - no_reboot_needed

- name: Ensure /var/log is mounted with noexec option
  mount:
    path: /var/log
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82008-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_noexec
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var/log --mountoptions="noexec"

Rule   Add nosuid Option to /boot   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /boot. The SUID and SGID permissions should not be required on the boot partition. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /boot.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from boot partitions.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_boot_nosuid
Identifiers and References

Identifiers:  CCE-81033-3

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /boot || { echo "Not remediating, because there is no record of /boot in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/boot" "nosuid" "" ""

	ensure_partition_is_mounted "/boot"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/boot'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81033-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nosuid
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81033-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nosuid
    - no_reboot_needed

- name: Make sure nosuid option is part of the to /boot options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81033-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nosuid
    - no_reboot_needed

- name: Ensure /boot is mounted with nosuid option
  mount:
    path: /boot
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81033-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_boot_nosuid
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /boot --mountoptions="nosuid"

Rule   Add nodev Option to /tmp   [ref]

The nodev mount option can be used to prevent device files from being created in /tmp. Legitimate character and block devices should not exist within temporary directories like /tmp. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_tmp_nodev
Identifiers and References

Identifiers:  CCE-82623-0

References:  NT28(R12), 1.1.3, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /tmp || { echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/tmp" "nodev" "" ""

	ensure_partition_is_mounted "/tmp"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82623-0
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nodev
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82623-0
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nodev
    - no_reboot_needed
    - unknown_severity

- name: Make sure nodev option is part of the to /tmp options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82623-0
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nodev
    - no_reboot_needed
    - unknown_severity

- name: Ensure /tmp is mounted with nodev option
  mount:
    path: /tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82623-0
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_nodev
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /tmp --mountoptions="nodev"

Rule   Add nodev Option to /var/tmp   [ref]

The nodev mount option can be used to prevent device files from being created in /var/tmp. Legitimate character and block devices should not exist within temporary directories like /var/tmp. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nodev
Identifiers and References

Identifiers:  CCE-82068-8

References:  NT28(R12), 1.1.8, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/tmp || { echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/tmp" "nodev" "" ""

	ensure_partition_is_mounted "/var/tmp"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82068-8
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nodev
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82068-8
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nodev
    - no_reboot_needed
    - unknown_severity

- name: Make sure nodev option is part of the to /var/tmp options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82068-8
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nodev
    - no_reboot_needed
    - unknown_severity

- name: Ensure /var/tmp is mounted with nodev option
  mount:
    path: /var/tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82068-8
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_nodev
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /var/tmp --mountoptions="nodev"

Rule   Add nosuid Option to /var/log   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /var/log. The SUID and SGID permissions should not be required in directories containing log files. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for log files.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_nosuid
Identifiers and References

Identifiers:  CCE-82065-4

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/log || { echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/log" "nosuid" "" ""

	ensure_partition_is_mounted "/var/log"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/log'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82065-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nosuid
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82065-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nosuid
    - no_reboot_needed

- name: Make sure nosuid option is part of the to /var/log options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82065-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nosuid
    - no_reboot_needed

- name: Ensure /var/log is mounted with nosuid option
  mount:
    path: /var/log
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82065-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_nosuid
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var/log --mountoptions="nosuid"

Rule   Add nodev Option to /var/log/audit   [ref]

The nodev mount option can be used to prevent device files from being created in /var/log/audit. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var/log/audit.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nodev
Identifiers and References

Identifiers:  CCE-82080-3

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/log/audit || { echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/log/audit" "nodev" "" ""

	ensure_partition_is_mounted "/var/log/audit"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/log/audit'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82080-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nodev
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82080-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nodev
    - no_reboot_needed

- name: Make sure nodev option is part of the to /var/log/audit options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82080-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nodev
    - no_reboot_needed

- name: Ensure /var/log/audit is mounted with nodev option
  mount:
    path: /var/log/audit
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82080-3
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nodev
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var/log/audit --mountoptions="nodev"

Rule   Add noexec Option to /var/log/audit   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /var/log/audit. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/log/audit.

Rationale:

Allowing users to execute binaries from directories containing audit log files such as /var/log/audit should never be necessary in normal operation and can expose the system to potential compromise.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_noexec
Identifiers and References

Identifiers:  CCE-82975-4

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/log/audit || { echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/log/audit" "noexec" "" ""

	ensure_partition_is_mounted "/var/log/audit"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/log/audit'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82975-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_noexec
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82975-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_noexec
    - no_reboot_needed

- name: Make sure noexec option is part of the to /var/log/audit options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
    - mount_info is defined and "noexec" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82975-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_noexec
    - no_reboot_needed

- name: Ensure /var/log/audit is mounted with noexec option
  mount:
    path: /var/log/audit
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82975-4
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_noexec
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var/log/audit --mountoptions="noexec"

Rule   Add nosuid Option to /var/log/audit   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /var/log/audit. The SUID and SGID permissions should not be required in directories containing audit log files. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/log/audit.

Rationale:

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for audit log files.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nosuid
Identifiers and References

Identifiers:  CCE-82921-8

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/log/audit || { echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/log/audit" "nosuid" "" ""

	ensure_partition_is_mounted "/var/log/audit"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/log/audit'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82921-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nosuid
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82921-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nosuid
    - no_reboot_needed

- name: Make sure nosuid option is part of the to /var/log/audit options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
    - mount_info is defined and "nosuid" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82921-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nosuid
    - no_reboot_needed

- name: Ensure /var/log/audit is mounted with nosuid option
  mount:
    path: /var/log/audit
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82921-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_log_audit_nosuid
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var/log/audit --mountoptions="nosuid"

Rule   Add nodev Option to /dev/shm   [ref]

The nodev mount option can be used to prevent creation of device files in /dev/shm. Legitimate character and block devices should not exist within temporary directories like /dev/shm. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_dev_shm_nodev
Identifiers and References

Identifiers:  CCE-80837-8

References:  1.1.5, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "no" = 'yes'; then
		assert_mount_point_in_fstab /dev/shm || { echo "Not remediating, because there is no record of /dev/shm in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/dev/shm" "nodev" "tmpfs" "tmpfs"

	ensure_partition_is_mounted "/dev/shm"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt  '/dev/shm'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80837-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nodev
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80837-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nodev
    - no_reboot_needed

- name: Make sure nodev option is part of the to /dev/shm options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80837-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nodev
    - no_reboot_needed

- name: Ensure /dev/shm is mounted with nodev option
  mount:
    path: /dev/shm
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80837-8
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_dev_shm_nodev
    - no_reboot_needed

Rule   Add noexec Option to /tmp   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Rationale:

Allowing users to execute binaries from world-writable directories such as /tmp should never be necessary in normal operation and can expose the system to potential compromise.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_tmp_noexec
Identifiers and References

Identifiers:  CCE-82139-7

References:  NT28(R12), 1.1.5, 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /tmp || { echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/tmp" "noexec" "" ""

	ensure_partition_is_mounted "/tmp"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82139-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_noexec
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82139-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_noexec
    - no_reboot_needed
    - unknown_severity

- name: Make sure noexec option is part of the to /tmp options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
    - mount_info is defined and "noexec" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82139-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_noexec
    - no_reboot_needed
    - unknown_severity

- name: Ensure /tmp is mounted with noexec option
  mount:
    path: /tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82139-7
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_tmp_noexec
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /tmp --mountoptions="noexec"

Rule   Add nodev Option to /var   [ref]

The nodev mount option can be used to prevent device files from being created in /var. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var.

Rationale:

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_nodev
Identifiers and References

Identifiers:  CCE-82062-1

References:  CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var || { echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var" "nodev" "" ""

	ensure_partition_is_mounted "/var"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82062-1
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_nodev
    - no_reboot_needed

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82062-1
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_nodev
    - no_reboot_needed

- name: Make sure nodev option is part of the to /var options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
    - mount_info is defined and "nodev" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82062-1
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_nodev
    - no_reboot_needed

- name: Ensure /var is mounted with nodev option
  mount:
    path: /var
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82062-1
    - NIST-800-53-AC-6
    - NIST-800-53-AC-6(1)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - configure_strategy
    - high_disruption
    - low_complexity
    - medium_severity
    - mount_option_var_nodev
    - no_reboot_needed


Complexity:low
Disruption:high
Strategy:enable

part /var --mountoptions="nodev"

Rule   Add noexec Option to /var/tmp   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /var/tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.

Rationale:

Allowing users to execute binaries from world-writable directories such as /var/tmp should never be necessary in normal operation and can expose the system to potential compromise.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_tmp_noexec
Identifiers and References

Identifiers:  CCE-82151-2

References:  NT28(R12), 1.1.10, SRG-OS-000368-GPOS-00154



function include_mount_options_functions {
	:
}

# $1: type of filesystem
# $2: new mount point option
# $3: filesystem of new mount point (used when adding new entry in fstab)
# $4: mount type of new mount point (used when adding new entry in fstab)
function ensure_mount_option_for_vfstype {
        local _vfstype="$1" _new_opt="$2" _filesystem=$3 _type=$4 _vfstype_points=()
        readarray -t _vfstype_points < <(grep -E "[[:space:]]${_vfstype}[[:space:]]" /etc/fstab | awk '{print $2}')

        for _vfstype_point in "${_vfstype_points[@]}"
        do
                ensure_mount_option_in_fstab "$_vfstype_point" "$_new_opt" "$_filesystem" "$_type"
        done
}

# $1: mount point
# $2: new mount point option
# $3: device or virtual string (used when adding new entry in fstab)
# $4: mount type of mount point (used when adding new entry in fstab)
function ensure_mount_option_in_fstab {
	local _mount_point="$1" _new_opt="$2" _device=$3 _type=$4
	local _mount_point_match_regexp="" _previous_mount_opts=""
	_mount_point_match_regexp="$(get_mount_point_regexp "$_mount_point")"

	if [ "$(grep -c "$_mount_point_match_regexp" /etc/fstab)" -eq 0 ]; then
		# runtime opts without some automatic kernel/userspace-added defaults
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
					| sed -E "s/(rw|defaults|seclabel|${_new_opt})(,|$)//g;s/,$//")
		[ "$_previous_mount_opts" ] && _previous_mount_opts+=","
		echo "${_device} ${_mount_point} ${_type} defaults,${_previous_mount_opts}${_new_opt} 0 0" >> /etc/fstab
	elif [ "$(grep "$_mount_point_match_regexp" /etc/fstab | grep -c "$_new_opt")" -eq 0 ]; then
		_previous_mount_opts=$(grep "$_mount_point_match_regexp" /etc/fstab | awk '{print $4}')
		sed -i "s|\(${_mount_point_match_regexp}.*${_previous_mount_opts}\)|\1,${_new_opt}|" /etc/fstab
	fi
}

# $1: mount point
function get_mount_point_regexp {
		printf "[[:space:]]%s[[:space:]]" "$1"
}

# $1: mount point
function assert_mount_point_in_fstab {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	grep "$_mount_point_match_regexp" -q /etc/fstab \
		|| { echo "The mount point '$1' is not even in /etc/fstab, so we can't set up mount options" >&2; return 1; }
}

# $1: mount point
function remove_defaults_from_fstab_if_overriden {
	local _mount_point_match_regexp
	_mount_point_match_regexp="$(get_mount_point_regexp "$1")"
	if grep "$_mount_point_match_regexp" /etc/fstab | grep -q "defaults,"
	then
		sed -i "s|\(${_mount_point_match_regexp}.*\)defaults,|\1|" /etc/fstab
	fi
}

# $1: mount point
function ensure_partition_is_mounted {
	local _mount_point="$1"
	mkdir -p "$_mount_point" || return 1
	if mountpoint -q "$_mount_point"; then
		mount -o remount --target "$_mount_point"
	else
		mount --target "$_mount_point"
	fi
}
include_mount_options_functions

function perform_remediation {
	# test "$mount_has_to_exist" = 'yes'
	if test "yes" = 'yes'; then
		assert_mount_point_in_fstab /var/tmp || { echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
	fi

	ensure_mount_option_in_fstab "/var/tmp" "noexec" "" ""

	ensure_partition_is_mounted "/var/tmp"
}

perform_remediation


Complexity:low
Disruption:high
Strategy:configure
- name: Check information associated to mountpoint
  command: findmnt --fstab '/var/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82151-2
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_noexec
    - no_reboot_needed
    - unknown_severity

- name: Create mount_info dictionary variable
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
    - '{{ device_name.stdout_lines[0].split() | list | lower }}'
    - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
    - device_name.stdout is defined and device_name.stdout_lines is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82151-2
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_noexec
    - no_reboot_needed
    - unknown_severity

- name: Make sure noexec option is part of the to /var/tmp options
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
    - mount_info is defined and "noexec" not in mount_info.options
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82151-2
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_noexec
    - no_reboot_needed
    - unknown_severity

- name: Ensure /var/tmp is mounted with noexec option
  mount:
    path: /var/tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
    - device_name.stdout is defined
    - (device_name.stdout | length > 0)
    - ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82151-2
    - configure_strategy
    - high_disruption
    - low_complexity
    - mount_option_var_tmp_noexec
    - no_reboot_needed
    - unknown_severity


Complexity:low
Disruption:high
Strategy:enable

part /var/tmp --mountoptions="noexec"
Group   Restrict Dynamic Mounting and Unmounting of Filesystems   Group contains 1 rule

[ref]   Linux includes a number of facilities for the automated addition and removal of filesystems on a running system. These facilities may be necessary in many environments, but this capability also carries some risk -- whether direct risk from allowing users to introduce arbitrary filesystems, or risk that software flaws in the automated mount facility itself could allow an attacker to compromise the system.

This command can be used to list the types of filesystems that are available to the currently executing kernel:

$ find /lib/modules/`uname -r`/kernel/fs -type f -name '*.ko'
If these filesystems are not required then they can be explicitly disabled in a configuratio file in /etc/modprobe.d.

Rule   Disable Mounting of cramfs   [ref]

To configure the system to prevent the cramfs kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem. The cramfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems. A cramfs image can be used without having to first decompress the image.

Rationale:

Removing support for unneeded filesystem types reduces the local attack surface of the server.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_cramfs_disabled
Identifiers and References

Identifiers:  CCE-81031-7

References:  1.1.1.1, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install cramfs" /etc/modprobe.d/cramfs.conf ; then
	sed -i 's/^install cramfs.*/install cramfs /bin/true/g' /etc/modprobe.d/cramfs.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/cramfs.conf
	echo "install cramfs /bin/true" >> /etc/modprobe.d/cramfs.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'cramfs' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/cramfs.conf
    regexp: cramfs
    line: install cramfs /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81031-7
    - NIST-800-171-3.4.6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - kernel_module_cramfs_disabled
    - low_complexity
    - low_severity
    - medium_disruption
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20cramfs%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_cramfs_disabled.conf
Group   Network Configuration and Firewalls   Group contains 11 groups and 31 rules

[ref]   Most systems must be connected to a network of some sort, and this brings with it the substantial risk of network attack. This section discusses the security impact of decisions about networking which must be made when configuring a system.

This section also discusses firewalls, network access controls, and other network security frameworks, which allow system-level rules to be written that can limit an attackers' ability to connect to your system. These rules can specify that network traffic should be allowed or denied from certain IP addresses, hosts, and networks. The rules can also specify which of the system's network services are available to particular hosts or networks.

Group   Wireless Networking   Group contains 1 group and 1 rule

[ref]   Wireless networking, such as 802.11 (WiFi) and Bluetooth, can present a security risk to sensitive or classified systems and networks. Wireless networking hardware is much more likely to be included in laptop or portable systems than in desktops or servers.

Removal of hardware provides the greatest assurance that the wireless capability remains disabled. Acquisition policies often include provisions to prevent the purchase of equipment that will be used in sensitive spaces and includes wireless capabilities. If it is impractical to remove the wireless hardware, and policy permits the device to enter sensitive spaces as long as wireless is disabled, efforts should instead focus on disabling wireless capability via software.

Group   Disable Wireless Through Software Configuration   Group contains 1 rule

[ref]   If it is impossible to remove the wireless hardware from the device in question, disable as much of it as possible through software. The following methods can disable software support for wireless networking, but note that these methods do not prevent malicious software or careless users from re-activating the devices.

Rule   Disable Bluetooth Kernel Module   [ref]

The kernel's module loading system can be configured to prevent loading of the Bluetooth module. Add the following to the appropriate /etc/modprobe.d configuration file to prevent the loading of the Bluetooth module:

install bluetooth /bin/true

Rationale:

If Bluetooth functionality must be disabled, preventing the kernel from loading the kernel module provides an additional safeguard against its activation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_bluetooth_disabled
Identifiers and References

Identifiers:  CCE-80832-9

References:  11, 12, 14, 15, 3, 8, 9, 5.13.1.3, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 3.1.16, CCI-000085, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, AC-18(a), AC-18(3), CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install bluetooth" /etc/modprobe.d/bluetooth.conf ; then
	sed -i 's/^install bluetooth.*/install bluetooth /bin/true/g' /etc/modprobe.d/bluetooth.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/bluetooth.conf
	echo "install bluetooth /bin/true" >> /etc/modprobe.d/bluetooth.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'bluetooth' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/bluetooth.conf
    regexp: bluetooth
    line: install bluetooth /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80832-9
    - CJIS-5.13.1.3
    - NIST-800-171-3.1.16
    - NIST-800-53-AC-18(3)
    - NIST-800-53-AC-18(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-MP-7
    - disable_strategy
    - kernel_module_bluetooth_disabled
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20bluetooth%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_bluetooth_disabled.conf
Group   iptables and ip6tables   Group contains 1 rule

[ref]   A host-based firewall called netfilter is included as part of the Linux kernel distributed with the system. It is activated by default. This firewall is controlled by the program iptables, and the entire capability is frequently referred to by this name. An analogous program called ip6tables handles filtering for IPv6.

Unlike TCP Wrappers, which depends on the network server program to support and respect the rules written, netfilter filtering occurs at the kernel level, before a program can even process the data from the network packet. As such, any program on the system is affected by the rules written.

This section provides basic information about strengthening the iptables and ip6tables configurations included with the system. For more complete information that may allow the construction of a sophisticated ruleset tailored to your environment, please consult the references at the end of this section.

Rule   Install iptables Package   [ref]

The iptables package can be installed with the following command:

$ sudo yum install iptables

Rationale:

iptables controls the Linux kernel network packet filtering code. iptables allows system operators to set up firewalls and IP masquerading, etc.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_iptables_installed
Identifiers and References

Identifiers:  CCE-82982-0

References:  3.4.1.1, CM-6(a), SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "iptables" ; then
    yum install -y "iptables"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure iptables is installed
  package:
    name: iptables
    state: present
  tags:
    - CCE-82982-0
    - NIST-800-53-CM-6(a)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_iptables_installed


Complexity:low
Disruption:low
Strategy:enable
include install_iptables

class install_iptables {
  package { 'iptables':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=iptables
Group   firewalld   Group contains 1 group and 2 rules

[ref]   The dynamic firewall daemon firewalld provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly.
A graphical configuration tool, firewall-config, is used to configure firewalld, which in turn uses iptables tool to communicate with Netfilter in the kernel which implements packet filtering.
The firewall service provided by firewalld is dynamic rather than static because changes to the configuration can be made at anytime and are immediately implemented. There is no need to save or apply the changes. No unintended disruption of existing network connections occurs as no part of the firewall has to be reloaded.

Group   Inspect and Activate Default firewalld Rules   Group contains 2 rules

[ref]   Firewalls can be used to separate networks into different zones based on the level of trust the user has decided to place on the devices and traffic within that network. NetworkManager informs firewalld to which zone an interface belongs. An interface's assigned zone can be changed by NetworkManager or via the firewall-config tool.
The zone settings in /etc/firewalld/ are a range of preset settings which can be quickly applied to a network interface. These are the zones provided by firewalld sorted according to the default trust level of the zones from untrusted to trusted:

  • drop

    Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.

  • block

    Any incoming network connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6. Only network connections initiated from within the system are possible.

  • public

    For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

  • external

    For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

  • dmz

    For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.

  • work

    For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

  • home

    For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

  • internal

    For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.

  • trusted

    All network connections are accepted.


It is possible to designate one of these zones to be the default zone. When interface connections are added to NetworkManager, they are assigned to the default zone. On installation, the default zone in firewalld is set to be the public zone.
To find out all the settings of a zone, for example the public zone, enter the following command as root:
# firewall-cmd --zone=public --list-all
Example output of this command might look like the following:
# firewall-cmd --zone=public --list-all
public
  interfaces:
  services: mdns dhcpv6-client ssh
  ports:
  forward-ports:
  icmp-blocks: source-quench
To view the network zones currently active, enter the following command as root:
# firewall-cmd --get-service
The following listing displays the result of this command on common Red Hat Enterprise Linux 8 system:
# firewall-cmd --get-service
amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
samba samba-client smtp ssh telnet tftp tftp-client transmission-client
vnc-server wbem-https
Finally to view the network zones that will be active after the next firewalld service reload, enter the following command as root:
# firewall-cmd --get-service --permanent

Rule   Install firewalld Package   [ref]

The firewalld package can be installed with the following command:

$ sudo yum install firewalld

Rationale:

The firewalld package should be installed to provide access control methods.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_firewalld_installed
Identifiers and References

Identifiers:  CCE-82998-6

References:  3.4.1.1, CM-6(a), SRG-OS-000480-GPOS-00227, SRG-OS-000298-GPOS-00116



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "firewalld" ; then
    yum install -y "firewalld"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure firewalld is installed
  package:
    name: firewalld
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82998-6
    - NIST-800-53-CM-6(a)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_firewalld_installed


Complexity:low
Disruption:low
Strategy:enable
include install_firewalld

class install_firewalld {
  package { 'firewalld':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=firewalld

Rule   Verify firewalld Enabled   [ref]

The firewalld service can be enabled with the following command:

$ sudo systemctl enable firewalld.service

Rationale:

Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_firewalld_enabled
Identifiers and References

Identifiers:  CCE-80877-4

References:  3.4.2.1, 11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.3, 3.4.7, CCI-000366, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a), PR.IP-1, FMT_MOF_EXT.1, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232



Complexity:low
Disruption:low
Strategy:enable

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" start 'firewalld.service'
"$SYSTEMCTL_EXEC" enable 'firewalld.service'


Complexity:low
Disruption:low
Strategy:enable
- name: Enable service firewalld
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable service firewalld
      service:
        name: firewalld
        enabled: 'yes'
        state: started
      when:
        - '"firewalld" in ansible_facts.packages'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80877-4
    - NIST-800-171-3.1.3
    - NIST-800-171-3.4.7
    - NIST-800-53-AC-4
    - NIST-800-53-CA-3(5)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-7(21)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_firewalld_enabled


Complexity:low
Disruption:low
Strategy:enable
include enable_firewalld

class enable_firewalld {
  service {'firewalld':
    enable => true,
    ensure => 'running',
  }
}
Group   Kernel Parameters Which Affect Networking   Group contains 2 groups and 16 rules

[ref]   The sysctl utility is used to set parameters which affect the operation of the Linux kernel. Kernel parameters which affect networking and have security implications are described here.

Group   Network Parameters for Hosts Only   Group contains 3 rules

[ref]   If the system is not going to be used as a router, then setting certain kernel parameters ensure that the host will not perform routing of network traffic.

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.send_redirects = 0

Rationale:

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects
Identifiers and References

Identifiers:  CCE-80918-6

References:  NT28(R22), 3.1.2, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for net.ipv4.conf.all.send_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.send_redirects="0"

#
# If net.ipv4.conf.all.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.send_redirects = 0" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.all.send_redirects' "0" 'CCE-80918-6'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl net.ipv4.conf.all.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.all.send_redirects
    value: '0'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80918-6
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5CM-6(a)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_all_send_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.send_redirects%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_send_redirects.conf

Rule   Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.ip_forward = 0

Warning:  Certain technologies such as virtual machines, containers, etc. rely on IPv4 forwarding to enable and use networking. Disabling IPv4 forwarding would cause those technologies to stop working. Therefore, this rule should not be used in profiles or benchmarks that target usage of IPv4 forwarding.
Rationale:

Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_forward
Identifiers and References

Identifiers:  CCE-81024-2

References:  NT28(R22), 3.1.1., 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), SC-5CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for net.ipv4.ip_forward
#
/sbin/sysctl -q -n -w net.ipv4.ip_forward="0"

#
# If net.ipv4.ip_forward present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.ip_forward = 0" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.ip_forward' "0" 'CCE-81024-2'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl net.ipv4.ip_forward is set to 0
  sysctl:
    name: net.ipv4.ip_forward
    value: '0'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81024-2
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5CM-6(a)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_ip_forward

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.send_redirects = 0

Rationale:

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects
Identifiers and References

Identifiers:  CCE-80921-0

References:  NT28(R22), 3.1.2, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable


#
# Set runtime for net.ipv4.conf.default.send_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.send_redirects="0"

#
# If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.default.send_redirects' "0" 'CCE-80921-0'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure sysctl net.ipv4.conf.default.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.default.send_redirects
    value: '0'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80921-0
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5CM-6(a)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_default_send_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.send_redirects%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_send_redirects.conf
Group   Network Related Kernel Runtime Parameters for Hosts and Routers   Group contains 13 rules

[ref]   Certain kernel parameters should be set for systems which are acting as either hosts or routers to improve the system's ability defend against certain types of IPv4 protocol attacks.

Rule   Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_echo_ignore_broadcasts = 1

Rationale:

Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.
Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_echo_ignore_broadcasts
Identifiers and References

Identifiers:  CCE-80922-8

References:  3.2.5, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5, DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value="1"

#
# Set runtime for net.ipv4.icmp_echo_ignore_broadcasts
#
/sbin/sysctl -q -n -w net.ipv4.icmp_echo_ignore_broadcasts="$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"

#
# If net.ipv4.icmp_echo_ignore_broadcasts present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.icmp_echo_ignore_broadcasts = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.icmp_echo_ignore_broadcasts' "$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value" 'CCE-80922-8'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_echo_ignore_broadcasts is set
  sysctl:
    name: net.ipv4.icmp_echo_ignore_broadcasts
    value: '{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80922-8
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_icmp_echo_ignore_broadcasts


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.icmp_echo_ignore_broadcasts%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_icmp_echo_ignore_broadcasts.conf

Rule   Enable Kernel Paremeter to Log Martian Packets on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.log_martians kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.log_martians = 1

Rationale:

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_log_martians
Identifiers and References

Identifiers:  CCE-81020-0

References:  3.2.4, 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000126, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_default_log_martians_value="1"

#
# Set runtime for net.ipv4.conf.default.log_martians
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.log_martians="$sysctl_net_ipv4_conf_default_log_martians_value"

#
# If net.ipv4.conf.default.log_martians present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.log_martians = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.default.log_martians' "$sysctl_net_ipv4_conf_default_log_martians_value" 'CCE-81020-0'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_default_log_martians_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_log_martians_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.log_martians is set
  sysctl:
    name: net.ipv4.conf.default.log_martians
    value: '{{ sysctl_net_ipv4_conf_default_log_martians_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81020-0
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5(3)(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - reboot_required
    - sysctl_net_ipv4_conf_default_log_martians
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.log_martians%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_log_martians.conf

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_source_route = 0

Rationale:

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures.
Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_source_route
Identifiers and References

Identifiers:  CCE-80920-2

References:  NT28(R22), 3.2.1, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_default_accept_source_route_value="0"

#
# Set runtime for net.ipv4.conf.default.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_source_route="$sysctl_net_ipv4_conf_default_accept_source_route_value"

#
# If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.accept_source_route = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.default.accept_source_route' "$sysctl_net_ipv4_conf_default_accept_source_route_value" 'CCE-80920-2'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv4.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv4_conf_default_accept_source_route_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80920-2
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_default_accept_source_route


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.accept_source_route%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_accept_source_route.conf

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.accept_source_route = 0

Rationale:

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_source_route
Identifiers and References

Identifiers:  CCE-81011-9

References:  NT28(R22), 3.2.1, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_all_accept_source_route_value="0"

#
# Set runtime for net.ipv4.conf.all.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_source_route="$sysctl_net_ipv4_conf_all_accept_source_route_value"

#
# If net.ipv4.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.accept_source_route = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.all.accept_source_route' "$sysctl_net_ipv4_conf_all_accept_source_route_value" 'CCE-81011-9'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.accept_source_route is set
  sysctl:
    name: net.ipv4.conf.all.accept_source_route
    value: '{{ sysctl_net_ipv4_conf_all_accept_source_route_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81011-9
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5CM-6(a)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_all_accept_source_route


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.accept_source_route%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_accept_source_route.conf

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_redirects = 0

Rationale:

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects
Identifiers and References

Identifiers:  CCE-80919-4

References:  NT28(R22), 3.2.2, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_default_accept_redirects_value="0"

#
# Set runtime for net.ipv4.conf.default.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_redirects="$sysctl_net_ipv4_conf_default_accept_redirects_value"

#
# If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.accept_redirects = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.default.accept_redirects' "$sysctl_net_ipv4_conf_default_accept_redirects_value" 'CCE-80919-4'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_default_accept_redirects_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80919-4
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_default_accept_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.accept_redirects%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_accept_redirects.conf

Rule   Disable Accepting ICMP Redirects for All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.accept_redirects = 0

Rationale:

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required."

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_redirects
Identifiers and References

Identifiers:  CCE-80917-8

References:  NT28(R22), 3.2.2, 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, 5.10.1.1, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000366, CCI-001503, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_all_accept_redirects_value="0"

#
# Set runtime for net.ipv4.conf.all.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_redirects="$sysctl_net_ipv4_conf_all_accept_redirects_value"

#
# If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.accept_redirects = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.all.accept_redirects' "$sysctl_net_ipv4_conf_all_accept_redirects_value" 'CCE-80917-8'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.all.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_all_accept_redirects_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80917-8
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_all_accept_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.accept_redirects%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_accept_redirects.conf

Rule   Configure Kernel Parameter for Accepting Secure Redirects By Default   [ref]

To set the runtime status of the net.ipv4.conf.default.secure_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.secure_redirects = 0

Rationale:

Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_secure_redirects
Identifiers and References

Identifiers:  CCE-81017-6

References:  NT28(R22), 3.2.3, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_default_secure_redirects_value="0"

#
# Set runtime for net.ipv4.conf.default.secure_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.secure_redirects="$sysctl_net_ipv4_conf_default_secure_redirects_value"

#
# If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.secure_redirects = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.default.secure_redirects' "$sysctl_net_ipv4_conf_default_secure_redirects_value" 'CCE-81017-6'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_default_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.default.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_default_secure_redirects_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81017-6
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_default_secure_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.secure_redirects%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_secure_redirects.conf

Rule   Enable Kernel Parameter to Use TCP Syncookies on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.tcp_syncookies = 1

Rationale:

A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies
Identifiers and References

Identifiers:  CCE-80923-6

References:  NT28(R22), 3.2.8, 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_tcp_syncookies_value="1"

#
# Set runtime for net.ipv4.tcp_syncookies
#
/sbin/sysctl -q -n -w net.ipv4.tcp_syncookies="$sysctl_net_ipv4_tcp_syncookies_value"

#
# If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.tcp_syncookies = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.tcp_syncookies' "$sysctl_net_ipv4_tcp_syncookies_value" 'CCE-80923-6'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_tcp_syncookies_value # promote to variable
  set_fact:
    sysctl_net_ipv4_tcp_syncookies_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.tcp_syncookies is set
  sysctl:
    name: net.ipv4.tcp_syncookies
    value: '{{ sysctl_net_ipv4_tcp_syncookies_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80923-6
    - CJIS-5.10.1.1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5(1)
    - NIST-800-53-SC-5(2)
    - NIST-800-53-SC-5(3)(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_tcp_syncookies


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.tcp_syncookies%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_tcp_syncookies.conf

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.rp_filter kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.rp_filter = 1

Rationale:

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_rp_filter
Identifiers and References

Identifiers:  CCE-81022-6

References:  NT28(R22), 3.2.7, 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_default_rp_filter_value="1"

#
# Set runtime for net.ipv4.conf.default.rp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.rp_filter="$sysctl_net_ipv4_conf_default_rp_filter_value"

#
# If net.ipv4.conf.default.rp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.rp_filter = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.default.rp_filter' "$sysctl_net_ipv4_conf_default_rp_filter_value" 'CCE-81022-6'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_default_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.rp_filter is set
  sysctl:
    name: net.ipv4.conf.default.rp_filter
    value: '{{ sysctl_net_ipv4_conf_default_rp_filter_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81022-6
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_default_rp_filter


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.rp_filter%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_rp_filter.conf

Rule   Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_ignore_bogus_error_responses = 1

Rationale:

Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses
Identifiers and References

Identifiers:  CCE-81023-4

References:  NT28(R22), 3.2.6, 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), SC-5, DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value="1"

#
# Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
#
/sbin/sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses="$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"

#
# If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.icmp_ignore_bogus_error_responses = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.icmp_ignore_bogus_error_responses' "$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value" 'CCE-81023-4'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_ignore_bogus_error_responses is set
  sysctl:
    name: net.ipv4.icmp_ignore_bogus_error_responses
    value: '{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81023-4
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5
    - disable_strategy
    - low_complexity
    - medium_disruption
    - reboot_required
    - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.icmp_ignore_bogus_error_responses%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_icmp_ignore_bogus_error_responses.conf

Rule   Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.log_martians kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.log_martians = 1

Rationale:

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_log_martians
Identifiers and References

Identifiers:  CCE-81018-4

References:  NT28(R22), 3.2.4, 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000126, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_all_log_martians_value="1"

#
# Set runtime for net.ipv4.conf.all.log_martians
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.log_martians="$sysctl_net_ipv4_conf_all_log_martians_value"

#
# If net.ipv4.conf.all.log_martians present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.log_martians = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.all.log_martians' "$sysctl_net_ipv4_conf_all_log_martians_value" 'CCE-81018-4'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_all_log_martians_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_log_martians_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.log_martians is set
  sysctl:
    name: net.ipv4.conf.all.log_martians
    value: '{{ sysctl_net_ipv4_conf_all_log_martians_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81018-4
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-5(3)(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - reboot_required
    - sysctl_net_ipv4_conf_all_log_martians
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.log_martians%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_log_martians.conf

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.rp_filter = 1

Rationale:

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter
Identifiers and References

Identifiers:  CCE-81021-8

References:  NT28(R22), 3.2.7, 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_all_rp_filter_value="1"

#
# Set runtime for net.ipv4.conf.all.rp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.rp_filter="$sysctl_net_ipv4_conf_all_rp_filter_value"

#
# If net.ipv4.conf.all.rp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.rp_filter = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.all.rp_filter' "$sysctl_net_ipv4_conf_all_rp_filter_value" 'CCE-81021-8'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_all_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.rp_filter is set
  sysctl:
    name: net.ipv4.conf.all.rp_filter
    value: '{{ sysctl_net_ipv4_conf_all_rp_filter_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81021-8
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_all_rp_filter


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.rp_filter%3D1
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_rp_filter.conf

Rule   Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.secure_redirects = 0

Rationale:

Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects
Identifiers and References

Identifiers:  CCE-81016-8

References:  NT28(R22), 3.2.3, 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001503, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv4_conf_all_secure_redirects_value="0"

#
# Set runtime for net.ipv4.conf.all.secure_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.secure_redirects="$sysctl_net_ipv4_conf_all_secure_redirects_value"

#
# If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.secure_redirects = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv4.conf.all.secure_redirects' "$sysctl_net_ipv4_conf_all_secure_redirects_value" 'CCE-81016-8'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv4_conf_all_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.all.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_all_secure_redirects_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81016-8
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - NIST-800-53-SC-7(a)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv4_conf_all_secure_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.secure_redirects%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_secure_redirects.conf
Group   IPv6   Group contains 1 group and 6 rules

[ref]   The system includes support for Internet Protocol version 6. A major and often-mentioned improvement over IPv4 is its enormous increase in the number of available addresses. Another important feature is its support for automatic configuration of many network settings.

Group   Configure IPv6 Settings if Necessary   Group contains 6 rules

[ref]   A major feature of IPv6 is the extent to which systems implementing it can automatically configure their networking devices using information from the network. From a security perspective, manually configuring important configuration information is preferable to accepting it from the network in an unauthenticated fashion.

Rule   Disable Accepting ICMP Redirects for All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_redirects = 0

Rationale:

An illicit ICMP redirect message could result in a man-in-the-middle attack.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_redirects
Identifiers and References

Identifiers:  CCE-81009-3

References:  NT28(R22), 3.3.2, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv6_conf_all_accept_redirects_value="0"

#
# Set runtime for net.ipv6.conf.all.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_redirects="$sysctl_net_ipv6_conf_all_accept_redirects_value"

#
# If net.ipv6.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_redirects = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv6.conf.all.accept_redirects' "$sysctl_net_ipv6_conf_all_accept_redirects_value" 'CCE-81009-3'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_redirects is set
  sysctl:
    name: net.ipv6.conf.all.accept_redirects
    value: '{{ sysctl_net_ipv6_conf_all_accept_redirects_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81009-3
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv6_conf_all_accept_redirects

Rule   Disable Accepting Router Advertisements on all IPv6 Interfaces by Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_ra kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.default.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_ra = 0

Rationale:

An illicit router advertisement message could result in a man-in-the-middle attack.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra
Identifiers and References

Identifiers:  CCE-81007-7

References:  3.2.9, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv6_conf_default_accept_ra_value="0"

#
# Set runtime for net.ipv6.conf.default.accept_ra
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_ra="$sysctl_net_ipv6_conf_default_accept_ra_value"

#
# If net.ipv6.conf.default.accept_ra present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_ra = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv6.conf.default.accept_ra' "$sysctl_net_ipv6_conf_default_accept_ra_value" 'CCE-81007-7'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_ra_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_ra_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_ra is set
  sysctl:
    name: net.ipv6.conf.default.accept_ra
    value: '{{ sysctl_net_ipv6_conf_default_accept_ra_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81007-7
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - reboot_required
    - sysctl_net_ipv6_conf_default_accept_ra
    - unknown_severity


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.default.accept_ra%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_default_accept_ra.conf

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_source_route = 0

Rationale:

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route
Identifiers and References

Identifiers:  CCE-81015-0

References:  NT28(R22), 3.2.1, 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv6_conf_default_accept_source_route_value="0"

#
# Set runtime for net.ipv6.conf.default.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_source_route="$sysctl_net_ipv6_conf_default_accept_source_route_value"

#
# If net.ipv6.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_source_route = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv6.conf.default.accept_source_route' "$sysctl_net_ipv6_conf_default_accept_source_route_value" 'CCE-81015-0'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_default_accept_source_route_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81015-0
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv6_conf_default_accept_source_route


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.default.accept_source_route%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_default_accept_source_route.conf

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_source_route = 0

Rationale:

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_source_route
Identifiers and References

Identifiers:  CCE-81013-5

References:  NT28(R22), 3.2.1, 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv6_conf_all_accept_source_route_value="0"

#
# Set runtime for net.ipv6.conf.all.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_source_route="$sysctl_net_ipv6_conf_all_accept_source_route_value"

#
# If net.ipv6.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_source_route = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv6.conf.all.accept_source_route' "$sysctl_net_ipv6_conf_all_accept_source_route_value" 'CCE-81013-5'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.all.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_all_accept_source_route_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81013-5
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv6_conf_all_accept_source_route


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.all.accept_source_route%3D0
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_all_accept_source_route.conf

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_redirects = 0

Rationale:

An illicit ICMP redirect message could result in a man-in-the-middle attack.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_redirects
Identifiers and References

Identifiers:  CCE-81010-1

References:  NT28(R22), 3.3.2, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv6_conf_default_accept_redirects_value="0"

#
# Set runtime for net.ipv6.conf.default.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_redirects="$sysctl_net_ipv6_conf_default_accept_redirects_value"

#
# If net.ipv6.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_redirects = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv6.conf.default.accept_redirects' "$sysctl_net_ipv6_conf_default_accept_redirects_value" 'CCE-81010-1'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv6.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv6_conf_default_accept_redirects_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81010-1
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required
    - sysctl_net_ipv6_conf_default_accept_redirects


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.default.accept_redirects%20%3D%200%0A
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_default_accept_redirects.conf

Rule   Configure Accepting Router Advertisements on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_ra kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_ra = 0

Rationale:

An illicit router advertisement message could result in a man-in-the-middle attack.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra
Identifiers and References

Identifiers:  CCE-81006-9

References:  3.2.9, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable

sysctl_net_ipv6_conf_all_accept_ra_value="0"

#
# Set runtime for net.ipv6.conf.all.accept_ra
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_ra="$sysctl_net_ipv6_conf_all_accept_ra_value"

#
# If net.ipv6.conf.all.accept_ra present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_ra = value" to /etc/sysctl.conf
#
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/sysctl.conf' '^net.ipv6.conf.all.accept_ra' "$sysctl_net_ipv6_conf_all_accept_ra_value" 'CCE-81006-9'


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_ra_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_ra_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_ra is set
  sysctl:
    name: net.ipv6.conf.all.accept_ra
    value: '{{ sysctl_net_ipv6_conf_all_accept_ra_value }}'
    state: present
    reload: true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81006-9
    - NIST-800-171-3.1.20
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - medium_disruption
    - reboot_required
    - sysctl_net_ipv6_conf_all_accept_ra
    - unknown_severity
Group   Uncommon Network Protocols   Group contains 5 rules

[ref]   The system includes support for several network protocols which are not commonly used. Although security vulnerabilities in kernel networking code are not frequently discovered, the consequences can be dramatic. Ensuring uncommon network protocols are disabled reduces the system's risk to attacks targeted at its implementation of those protocols.

Warning:  Although these protocols are not commonly used, avoid disruption in your network environment by ensuring they are not needed prior to disabling them.

Rule   Disable IEEE 1394 (FireWire) Support   [ref]

The IEEE 1394 (FireWire) is a serial bus standard for high-speed real-time communication. To configure the system to prevent the firewire-core kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install firewire-core /bin/true

Rationale:

Disabling FireWire protects the system against exploitation of any flaws in its implementation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_firewire-core_disabled
Identifiers and References

Identifiers:  CCE-82005-0

References:  FMT_SMF_EXT.1, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install firewire-core" /etc/modprobe.d/firewire-core.conf ; then
	sed -i 's/^install firewire-core.*/install firewire-core /bin/true/g' /etc/modprobe.d/firewire-core.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/firewire-core.conf
	echo "install firewire-core /bin/true" >> /etc/modprobe.d/firewire-core.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'firewire-core' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/firewire-core.conf
    regexp: firewire-core
    line: install firewire-core /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82005-0
    - disable_strategy
    - kernel_module_firewire-core_disabled
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20firewire-core%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_firewire-core_disabled.conf

Rule   Disable CAN Support   [ref]

The Controller Area Network (CAN) is a serial communications protocol which was initially developed for automotive and is now also used in marine, industrial, and medical applications. To configure the system to prevent the can kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install can /bin/true

Rationale:

Disabling CAN protects the system against exploitation of any flaws in its implementation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_can_disabled
Identifiers and References

Identifiers:  CCE-82059-7

References:  FMT_SMF_EXT.1, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install can" /etc/modprobe.d/can.conf ; then
	sed -i 's/^install can.*/install can /bin/true/g' /etc/modprobe.d/can.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/can.conf
	echo "install can /bin/true" >> /etc/modprobe.d/can.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'can' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/can.conf
    regexp: can
    line: install can /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82059-7
    - disable_strategy
    - kernel_module_can_disabled
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20can%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_can_disabled.conf

Rule   Disable TIPC Support   [ref]

The Transparent Inter-Process Communication (TIPC) protocol is designed to provide communications between nodes in a cluster. To configure the system to prevent the tipc kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install tipc /bin/true

Warning:  This configuration baseline was created to deploy the base operating system for general purpose workloads. When the operating system is configured for certain purposes, such as a node in High Performance Computing cluster, it is expected that the tipc kernel module will be loaded.
Rationale:

Disabling TIPC protects the system against exploitation of any flaws in its implementation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_tipc_disabled
Identifiers and References

Identifiers:  CCE-82297-3

References:  3.3.4, 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, FMT_SMF_EXT.1, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install tipc" /etc/modprobe.d/tipc.conf ; then
	sed -i 's/^install tipc.*/install tipc /bin/true/g' /etc/modprobe.d/tipc.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/tipc.conf
	echo "install tipc /bin/true" >> /etc/modprobe.d/tipc.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'tipc' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/tipc.conf
    regexp: tipc
    line: install tipc /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82297-3
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - kernel_module_tipc_disabled
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20tipc%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_tipc_disabled.conf

Rule   Disable SCTP Support   [ref]

The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. To configure the system to prevent the sctp kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install sctp /bin/true

Rationale:

Disabling SCTP protects the system against exploitation of any flaws in its implementation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_sctp_disabled
Identifiers and References

Identifiers:  CCE-80834-5

References:  3.5.2, 11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install sctp" /etc/modprobe.d/sctp.conf ; then
	sed -i 's/^install sctp.*/install sctp /bin/true/g' /etc/modprobe.d/sctp.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/sctp.conf
	echo "install sctp /bin/true" >> /etc/modprobe.d/sctp.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'sctp' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/sctp.conf
    regexp: sctp
    line: install sctp /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80834-5
    - CJIS-5.10.1
    - NIST-800-171-3.4.6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - kernel_module_sctp_disabled
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20sctp%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_sctp_disabled.conf

Rule   Disable ATM Support   [ref]

The Asynchronous Transfer Mode (ATM) is a protocol operating on network, data link, and physical layers, based on virtual circuits and virtual paths. To configure the system to prevent the atm kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install atm /bin/true

Rationale:

Disabling ATM protects the system against exploitation of any flaws in its implementation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_atm_disabled
Identifiers and References

Identifiers:  CCE-82028-2

References:  FMT_SMF_EXT.1, SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
if LC_ALL=C grep -q -m 1 "^install atm" /etc/modprobe.d/atm.conf ; then
	sed -i 's/^install atm.*/install atm /bin/true/g' /etc/modprobe.d/atm.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/atm.conf
	echo "install atm /bin/true" >> /etc/modprobe.d/atm.conf
fi


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'atm' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/atm.conf
    regexp: atm
    line: install atm /bin/true
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82028-2
    - disable_strategy
    - kernel_module_atm_disabled
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,install%20atm%20/bin/true%0A
        filesystem: root
        mode: 0644
        path: /etc/modprobe.d/75-kernel_module_atm_disabled.conf
Group   Services   Group contains 10 groups and 26 rules

[ref]   The best protection against vulnerable software is running less software. This section describes how to review the software which Red Hat Enterprise Linux 8 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Red Hat Enterprise Linux 8 system and provides guidance about which ones can be safely disabled.

Red Hat Enterprise Linux 8 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Red Hat Enterprise Linux 8 systems, it is highly recommended to select the minimal packages and then build up the system from there.

Group   SSH Server   Group contains 1 group and 13 rules

[ref]   The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, through the use of public key cryptography. The implementation included with the system is called OpenSSH, and more detailed documentation is available from its website, https://www.openssh.com. Its server program is called sshd and provided by the RPM package openssh-server.

Group   Configure OpenSSH Server if Necessary   Group contains 11 rules

[ref]   If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file /etc/ssh/sshd_config. The following recommendations can be applied to this file. See the sshd_config(5) man page for more detailed information.

Rule   Set SSH Client Alive Max Count   [ref]

To ensure the SSH idle timeout occurs precisely when the ClientAliveInterval is set, edit /etc/ssh/sshd_config as follows:

ClientAliveCountMax 0

Rationale:

This ensures a user login will be terminated as soon as the ClientAliveInterval is reached.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_keepalive
Identifiers and References

Identifiers:  CCE-80907-9

References:  5.2.13, 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000480-VMM-002000




var_sshd_set_keepalive="0"

if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_sshd_set_keepalive # promote to variable
  set_fact:
    var_sshd_set_keepalive: !!str 0
  tags:
    - always

- name: Set SSH Client Alive Max Count
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*ClientAliveCountMax\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: ClientAliveCountMax {{ var_sshd_set_keepalive }}
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80907-9
    - CJIS-5.5.6
    - NIST-800-171-3.1.11
    - NIST-800-53-AC-12
    - NIST-800-53-AC-17(a)
    - NIST-800-53-AC-2(5)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-10
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_set_keepalive


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Force frequent session key renegotiation   [ref]

The RekeyLimit parameter specifies how often the session key of the is renegotiated, both in terms of amount of data that may be transmitted and the time elapsed. To decrease the default limits, put line RekeyLimit 1G 1h to file /etc/ssh/sshd_config.

Rationale:

By decreasing the limit based on the amount of data and enabling time-based limit, effects of potential attacks against encryption keys are limited.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_rekey_limit
Identifiers and References

Identifiers:  CCE-82177-7

References:  FCS_SSHS_EXT.1, SRG-OS-000480-GPOS-00227




var_rekey_limit_size="1G"

var_rekey_limit_time="1h"



if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*RekeyLimit\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "RekeyLimit $var_rekey_limit_size $var_rekey_limit_time" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "RekeyLimit $var_rekey_limit_size $var_rekey_limit_time" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:configure
- name: XCCDF Value var_rekey_limit_size # promote to variable
  set_fact:
    var_rekey_limit_size: !!str 1G
  tags:
    - always
- name: XCCDF Value var_rekey_limit_time # promote to variable
  set_fact:
    var_rekey_limit_time: !!str 1h
  tags:
    - always

- name: Force frequent session key renegotiation
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*RekeyLimit\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: RekeyLimit {{ var_rekey_limit_size }} {{ var_rekey_limit_time }}
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82177-7
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - sshd_rekey_limit

Rule   Enable Use of Strict Mode Checking   [ref]

SSHs StrictModes option checks file and ownership permissions in the user's home directory .ssh folder before accepting login. If world- writable permissions are found, logon is rejected. To enable StrictModes in SSH, add or correct the following line in the /etc/ssh/sshd_config file:

StrictModes yes

Rationale:

If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_enable_strictmodes
Identifiers and References

Identifiers:  CCE-80904-6

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-6, AC-17(a), CM-6(a), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, SRG-OS-000480-VMM-002000



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*StrictModes\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "StrictModes yes" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "StrictModes yes" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Enable Use of Strict Mode Checking
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*StrictModes\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: StrictModes yes
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80904-6
    - NIST-800-171-3.1.12
    - NIST-800-53-AC-17(a)
    - NIST-800-53-AC-6
    - NIST-800-53-CM-6(a)
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_enable_strictmodes


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Disable GSSAPI Authentication   [ref]

Unless needed, SSH should not permit extraneous or unnecessary authentication mechanisms like GSSAPI. To disable GSSAPI authentication, add or correct the following line in the /etc/ssh/sshd_config file:

GSSAPIAuthentication no

Rationale:

GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_gssapi_auth
Identifiers and References

Identifiers:  CCE-80897-2

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000318, CCI-000368, CCI-001812, CCI-001813, CCI-001814, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-7(a), CM-7(b), CM-6(a), AC-17(a), PR.IP-1, FIA_AFL.1, SRG-OS-000364-GPOS-00151, SRG-OS-000480-VMM-002000



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*GSSAPIAuthentication\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "GSSAPIAuthentication no" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "GSSAPIAuthentication no" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable GSSAPI Authentication
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*GSSAPIAuthentication\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: GSSAPIAuthentication no
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80897-2
    - NIST-800-171-3.1.12
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_disable_gssapi_auth


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Disable SSH Access via Empty Passwords   [ref]

To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in /etc/ssh/sshd_config:

PermitEmptyPasswords no

Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.

Rationale:

Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.

Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords
Identifiers and References

Identifiers:  CCE-80896-4

References:  NT007(R17), 5.2.11, 11, 12, 13, 14, 15, 16, 18, 3, 5, 9, 5.5.6, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, 3.1.1, 3.1.5, CCI-000366, CCI-000766, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, FIA_AFL.1, SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-VMM-002000



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "PermitEmptyPasswords no" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "PermitEmptyPasswords no" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable SSH Access via Empty Passwords
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*PermitEmptyPasswords\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: PermitEmptyPasswords no
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80896-4
    - CJIS-5.5.6
    - NIST-800-171-3.1.1
    - NIST-800-171-3.1.5
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - high_severity
    - low_complexity
    - low_disruption
    - no_reboot_needed
    - restrict_strategy
    - sshd_disable_empty_passwords


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Set SSH Idle Timeout Interval   [ref]

SSH allows administrators to set an idle timeout interval. After this interval has passed, the idle user will be automatically logged out.

To set an idle timeout interval, edit the following line in /etc/ssh/sshd_config as follows:

ClientAliveInterval 840


The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600.

If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.

Rationale:

Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_idle_timeout
Identifiers and References

Identifiers:  CCE-80906-1

References:  NT28(R29), 5.2.13, 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175, SRG-OS-000480-VMM-002000




sshd_idle_timeout_value="840"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/ssh/sshd_config' '^ClientAliveInterval' $sshd_idle_timeout_value 'CCE-80906-1' '%s %s'


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value sshd_idle_timeout_value # promote to variable
  set_fact:
    sshd_idle_timeout_value: !!str 840
  tags:
    - always

- name: Set SSH Idle Timeout Interval
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*ClientAliveInterval\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: ClientAliveInterval {{ sshd_idle_timeout_value }}
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80906-1
    - CJIS-5.5.6
    - NIST-800-171-3.1.11
    - NIST-800-53-AC-12
    - NIST-800-53-AC-17(a)
    - NIST-800-53-AC-17(a)
    - NIST-800-53-AC-2(5)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-10
    - PCI-DSS-Req-8.1.8
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_set_idle_timeout


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Disable Host-Based Authentication   [ref]

SSH's cryptographic host-based authentication is more secure than .rhosts authentication. However, it is not recommended that hosts unilaterally trust one another, even within an organization.

To disable host-based authentication, add or correct the following line in /etc/ssh/sshd_config:

HostbasedAuthentication no

Rationale:

SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_disable_host_auth
Identifiers and References

Identifiers:  CCE-80786-7

References:  5.2.9, 11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-3, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_AFL.1, SRG-OS-000480-GPOS-00229, SRG-OS-000480-VMM-002000



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "HostbasedAuthentication no" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "HostbasedAuthentication no" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable Host-Based Authentication
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*HostbasedAuthentication\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: HostbasedAuthentication no
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80786-7
    - CJIS-5.5.6
    - NIST-800-171-3.1.12
    - NIST-800-53-AC-17(a)
    - NIST-800-53-AC-3
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_host_auth
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018%2F04%2F09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D%2Fusr%2Flocal%2Fbin%3A%2Fusr%2Fbin%3A%2Fusr%2Flocal%2Fsbin%3A%2Fusr%2Fsbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_rsa_key%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_ecdsa_key%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20%2Fetc%2Fsysconfig%2Fsshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh%2Fauthorized_keys%20and%20.ssh%2Fauthorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh%2Fauthorized_keys%0AAuthorizedKeysFile%09.ssh%2Fauthorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20%2Fetc%2Fssh%2Fssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~%2F.ssh%2Fknown_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~%2F.rhosts%20and%20~%2F.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s%2Fkey%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20%2Fetc%2Fpam.d%2Fsshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20%2Fvar%2Frun%2Fsshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20%2Fetc%2Fissue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09%2Fusr%2Flibexec%2Fopenssh%2Fsftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Disable Kerberos Authentication   [ref]

Unless needed, SSH should not permit extraneous or unnecessary authentication mechanisms like Kerberos. To disable Kerberos authentication, add or correct the following line in the /etc/ssh/sshd_config file:

KerberosAuthentication no

Rationale:

Kerberos authentication for SSH is often implemented using GSSAPI. If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementations may be subject to exploitation.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_kerb_auth
Identifiers and References

Identifiers:  CCE-80898-0

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000318, CCI-000368, CCI-001812, CCI-001813, CCI-001814, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, FIA_AFL.1, SRG-OS-000364-GPOS-00151, SRG-OS-000480-VMM-002000



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*KerberosAuthentication\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "KerberosAuthentication no" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "KerberosAuthentication no" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable Kerberos Authentication
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*KerberosAuthentication\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: KerberosAuthentication no
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80898-0
    - NIST-800-171-3.1.12
    - NIST-800-53-AC-17(a)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_disable_kerb_auth


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   Enable SSH Warning Banner   [ref]

To enable the warning banner and ensure it is consistent across the system, add or correct the following line in /etc/ssh/sshd_config:

Banner /etc/issue
Another section contains information on how to create an appropriate system-wide warning banner.

Rationale:

The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_enable_warning_banner
Identifiers and References

Identifiers:  CCE-80905-3

References:  5.2.15, 1, 12, 15, 16, 5.5.6, DSS05.04, DSS05.10, DSS06.10, 3.1.9, CCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), AC-17(a), CM-6(a), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000228-GPOS-00088, SRG-OS-000023-VMM-000060, SRG-OS-000024-VMM-000070



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/ssh/sshd_config" ] ; then
    LC_ALL=C sed -i "/^\s*Banner\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "Banner /etc/issue" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "Banner /etc/issue" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Enable SSH Warning Banner
  block:

    - name: Deduplicate values from /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: false
        regexp: (?i)^\s*Banner\s+
        state: absent

    - name: Insert correct line to /etc/ssh/sshd_config
      lineinfile:
        path: /etc/ssh/sshd_config
        create: true
        line: Banner /etc/issue
        state: present
        insertbefore: ^[#\s]*Match
        validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-80905-3
    - CJIS-5.5.6
    - NIST-800-171-3.1.9
    - NIST-800-53-AC-17(a)
    - NIST-800-53-AC-8(a)
    - NIST-800-53-AC-8(c)
    - NIST-800-53-CM-6(a)
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_enable_warning_banner


Complexity:low
Disruption:low
Strategy:restrict
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,%0A%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018/04/09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D/usr/local/bin%3A/usr/bin%3A/usr/local/sbin%3A/usr/sbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20/etc/ssh/ssh_host_rsa_key%0AHostKey%20/etc/ssh/ssh_host_ecdsa_key%0AHostKey%20/etc/ssh/ssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20/etc/sysconfig/sshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh/authorized_keys%20and%20.ssh/authorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh/authorized_keys%0AAuthorizedKeysFile%09.ssh/authorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20/etc/ssh/ssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~/.ssh/known_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~/.rhosts%20and%20~/.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s/key%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20/etc/pam.d/sshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20/var/run/sshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20/etc/issue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09/usr/libexec/openssh/sftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        filesystem: root
        mode: 0600
        path: /etc/ssh/sshd_config

Rule   SSH server uses strong entropy to seed   [ref]

To set up SSH server to use entropy from a high-quality source, edit the /etc/sysconfig/sshd file. The SSH_USE_STRONG_RNG configuration value determines how many bytes of entropy to use, so make sure that the file contains line

SSH_USE_STRONG_RNG=32

Warning:  This setting can cause problems on computers without the hardware random generator, because insufficient entropy causes the connection to be blocked until enough entropy is available.
Rationale:

SSH implementation in RHEL8 uses the openssl library, which doesn't use high-entropy sources by default. Randomness is needed to generate data-encryption keys, and as plaintext padding and initialization vectors in encryption algorithms, and high-quality entropy elliminates the possibility that the output of the random number generator used by SSH would be known to potential attackers.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_use_strong_rng
Identifiers and References

Identifiers:  CCE-82462-3

References:  FIA_AFL.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/sysconfig/sshd" ] ; then
    LC_ALL=C sed -i "/^\s*SSH_USE_STRONG_RNG=/d" "/etc/sysconfig/sshd"
else
    touch "/etc/sysconfig/sshd"
fi
cp "/etc/sysconfig/sshd" "/etc/sysconfig/sshd.bak"
# Insert before the line matching the regex '^#\s*SSH_USE_STRONG_RNG'.
line_number="$(LC_ALL=C grep -n "^#\s*SSH_USE_STRONG_RNG" "/etc/sysconfig/sshd.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^#\s*SSH_USE_STRONG_RNG', insert at
    # the end of the file.
    printf '%s\n' "SSH_USE_STRONG_RNG=32" >> "/etc/sysconfig/sshd"
else
    head -n "$(( line_number - 1 ))" "/etc/sysconfig/sshd.bak" > "/etc/sysconfig/sshd"
    printf '%s\n' "SSH_USE_STRONG_RNG=32" >> "/etc/sysconfig/sshd"
    tail -n "+$(( line_number ))" "/etc/sysconfig/sshd.bak" >> "/etc/sysconfig/sshd"
fi
# Clean up after ourselves.
rm "/etc/sysconfig/sshd.bak"


Complexity:low
Disruption:low
Strategy:restrict
- name: Setting unquoted shell-style assignment of 'SSH_USE_STRONG_RNG' to '32' in
    '/etc/sysconfig/sshd'
  block:

    - name: Deduplicate values from /etc/sysconfig/sshd
      lineinfile:
        path: /etc/sysconfig/sshd
        create: false
        regexp: ^\s*SSH_USE_STRONG_RNG=
        state: absent

    - name: Insert correct line to /etc/sysconfig/sshd
      lineinfile:
        path: /etc/sysconfig/sshd
        create: true
        line: SSH_USE_STRONG_RNG=32
        state: present
        insertbefore: ^# SSH_USE_STRONG_RNG
        validate: /usr/bin/bash -n %s
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82462-3
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - sshd_use_strong_rng

Rule   Install OpenSSH client software   [ref]

The openssh-clients package can be installed with the following command:

$ sudo yum install openssh-clients

Rationale:

This package includes utilities to make encrypted connections and transfer files securely to SSH servers.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_openssh-clients_installed
Identifiers and References

Identifiers:  CCE-82722-0

References:  FIA_UAU.5, FTP_ITC_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "openssh-clients" ; then
    yum install -y "openssh-clients"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure openssh-clients is installed
  package:
    name: openssh-clients
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82722-0
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_openssh-clients_installed


Complexity:low
Disruption:low
Strategy:enable
include install_openssh-clients

class install_openssh-clients {
  package { 'openssh-clients':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=openssh-clients

Rule   Install the OpenSSH Server Package   [ref]

The openssh-server package should be installed. The openssh-server package can be installed with the following command:

$ sudo yum install openssh-server

Rationale:

Without protection of the transmitted information, confidentiality, and integrity may be compromised because unprotected communications can be intercepted and either read or altered.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_openssh-server_installed
Identifiers and References

Identifiers:  CCE-83303-8

References:  13, 14, APO01.06, DSS05.02, DSS05.04, DSS05.07, DSS06.02, DSS06.06, CCI-002418, CCI-002420, CCI-002421, CCI-002422, SR 3.1, SR 3.8, SR 4.1, SR 4.2, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), PR.DS-2, PR.DS-5, FIA_UAU.5, FTP_ITC_EXT.1, SRG-OS-000423-GPOS-00187, SRG-OS-000423-GPOS-00188, SRG-OS-000423-GPOS-00189, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190, SRG-OS000423-GPOS-00190



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "openssh-server" ; then
    yum install -y "openssh-server"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure openssh-server is installed
  package:
    name: openssh-server
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-83303-8
    - NIST-800-53-CM-6(a)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_openssh-server_installed


Complexity:low
Disruption:low
Strategy:enable
include install_openssh-server

class install_openssh-server {
  package { 'openssh-server':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=openssh-server
Group   Base Services   Group contains 1 rule

[ref]   This section addresses the base services that are installed on a Red Hat Enterprise Linux 8 default installation which are not covered in other sections. Some of these services listen on the network and should be treated with particular discretion. Other services are local system utilities that may or may not be extraneous. In general, system services should be disabled if not required.

Rule   Uninstall Automatic Bug Reporting Tool (abrt)   [ref]

The Automatic Bug Reporting Tool (abrt) collects and reports crash data when an application crash is detected. Using a variety of plugins, abrt can email crash reports to system administrators, log crash reports to files, or forward crash reports to a centralized issue tracking system such as RHTSupport. The abrt package can be removed with the following command:

$ sudo yum erase abrt

Rationale:

Mishandling crash data could expose sensitive information about vulnerabilities in software executing on the system, as well as sensitive information from within a process's address space or registers.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_abrt_removed
Identifiers and References

Identifiers:  CCE-80948-3

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove abrt
#	   from the system, and may remove any packages
#	   that depend on abrt. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "abrt" ; then
    yum remove -y "abrt"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure abrt is removed
  package:
    name: abrt
    state: absent
  tags:
    - CCE-80948-3
    - disable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_abrt_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_abrt

class remove_abrt {
  package { 'abrt':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=abrt
Group   Application Whitelisting Daemon   Group contains 2 rules

[ref]   Fapolicyd (File Access Policy Daemon) implements application whitelisting to decide file access rights. Applications that are known via a reputation source are allowed access while unknown applications are not. The daemon makes use of the kernel's fanotify interface to determine file access rights.

Rule   Install fapolicyd Package   [ref]

The fapolicyd package can be installed with the following command:

$ sudo yum install fapolicyd

Rationale:

fapolicyd (File Access Policy Daemon) implements application whitelisting to decide file access rights.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_fapolicyd_installed
Identifiers and References

Identifiers:  CCE-82191-8

References:  CM-6(a), SI-4(22), SRG-OS-000370-GPOS-00155



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "fapolicyd" ; then
    yum install -y "fapolicyd"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure fapolicyd is installed
  package:
    name: fapolicyd
    state: present
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82191-8
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-4(22)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_fapolicyd_installed


Complexity:low
Disruption:low
Strategy:enable
include install_fapolicyd

class install_fapolicyd {
  package { 'fapolicyd':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=fapolicyd

Rule   Enable the File Access Policy Service   [ref]

The File Access Policy service should be enabled. The fapolicyd service can be enabled with the following command:

$ sudo systemctl enable fapolicyd.service

Rationale:

The fapolicyd service (File Access Policy Daemon) implements application whitelisting to decide file access rights.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_fapolicyd_enabled
Identifiers and References

Identifiers:  CCE-82249-4

References:  CM-6(a), SI-4(22), FMT_SMF_EXT.1, SRG-OS-000370-GPOS-00155



Complexity:low
Disruption:low
Strategy:enable

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" start 'fapolicyd.service'
"$SYSTEMCTL_EXEC" enable 'fapolicyd.service'


Complexity:low
Disruption:low
Strategy:enable
- name: Enable service fapolicyd
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable service fapolicyd
      service:
        name: fapolicyd
        enabled: 'yes'
        state: started
      when:
        - '"fapolicyd" in ansible_facts.packages'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82249-4
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-4(22)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_fapolicyd_enabled


Complexity:low
Disruption:low
Strategy:enable
include enable_fapolicyd

class enable_fapolicyd {
  service {'fapolicyd':
    enable => true,
    ensure => 'running',
  }
}
Group   USBGuard daemon   Group contains 4 rules

[ref]   The USBGuard daemon enforces the USB device authorization policy for all USB devices.

Rule   Install usbguard Package   [ref]

The usbguard package can be installed with the following command:

$ sudo yum install usbguard

Rationale:

usbguard is a software framework that helps to protect against rogue USB devices by implementing basic whitelisting/blacklisting capabilities based on USB device attributes.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_usbguard_installed
Identifiers and References

Identifiers:  CCE-82959-8

References:  SRG-OS-000378-GPOS-00163



Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "usbguard" ; then
    yum install -y "usbguard"
fi


Complexity:low
Disruption:low
Strategy:enable
- name: Ensure usbguard is installed
  package:
    name: usbguard
    state: present
  tags:
    - CCE-82959-8
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_usbguard_installed


Complexity:low
Disruption:low
Strategy:enable
include install_usbguard

class install_usbguard {
  package { 'usbguard':
    ensure => 'installed',
  }
}


Complexity:low
Disruption:low
Strategy:enable

package --add=usbguard

Rule   Enable the USBGuard Service   [ref]

The USBGuard service should be enabled. The usbguard service can be enabled with the following command:

$ sudo systemctl enable usbguard.service

Rationale:

The usbguard service must be running in order to enforce the USB device authorization policy for all USB devices.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_usbguard_enabled
Identifiers and References

Identifiers:  CCE-82853-3

References:  FMT_SMF_EXT.1, SRG-OS-000378-GPOS-00163



Complexity:low
Disruption:low
Strategy:enable

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" start 'usbguard.service'
"$SYSTEMCTL_EXEC" enable 'usbguard.service'


Complexity:low
Disruption:low
Strategy:enable
- name: Enable service usbguard
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable service usbguard
      service:
        name: usbguard
        enabled: 'yes'
        state: started
      when:
        - '"usbguard" in ansible_facts.packages'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82853-3
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_usbguard_enabled


Complexity:low
Disruption:low
Strategy:enable
include enable_usbguard

class enable_usbguard {
  service {'usbguard':
    enable => true,
    ensure => 'running',
  }
}

Rule   Authorize Human Interface Devices and USB hubs in USBGuard daemon   [ref]

To allow authorization of USB devices combining human interface device and hub capabilities by USBGuard daemon, add the line allow with-interface match_all { 03:*:* 09:00:* } to /etc/usbguard/rules.conf.

Warning:  This rule should be understood primarily as a convenience administration feature. This rule ensures that if the USBGuard default rules.conf file is present, it will alter it so that USB human interface devices and hubs are allowed. However, if the rules.conf file is altered by system administrator, the rule does not check if USB human interface devices and hubs are allowed. This assumes that an administrator modified the file with some purpose in mind.
Rationale:

Without allowing Human Interface Devices, it might not be possible to interact with the system. Without allowing hubs, it might not be possible to use any USB devices on the system.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_usbguard_allow_hid_and_hub
Identifiers and References

Identifiers:  CCE-82368-2

References:  FMT_SMF_EXT.1, SRG-OS-000114-GPOS-00059



#!/bin/bash


echo "allow with-interface match-all { 03:*:* 09:00:* }" >> /etc/usbguard/rules.conf

Rule   Log USBGuard daemon audit events using Linux Audit   [ref]

To configure USBGuard daemon to log via Linux Audit (as opposed directly to a file), AuditBackend option in /etc/usbguard/usbguard-daemon.conf needs to be set to LinuxAudit.

Rationale:

Using the Linux Audit logging allows for centralized trace of events.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_usbguard_auditbackend
Identifiers and References

Identifiers:  CCE-82168-6

References:  FMT_SMF_EXT.1, SRG-OS-000062-GPOS-00031



Complexity:low
Disruption:low
Strategy:restrict
if [ -e "/etc/usbguard/usbguard-daemon.conf" ] ; then
    LC_ALL=C sed -i "/^\s*AuditBackend=/d" "/etc/usbguard/usbguard-daemon.conf"
else
    touch "/etc/usbguard/usbguard-daemon.conf"
fi
cp "/etc/usbguard/usbguard-daemon.conf" "/etc/usbguard/usbguard-daemon.conf.bak"
# Insert at the end of the file
printf '%s\n' "AuditBackend=LinuxAudit" >> "/etc/usbguard/usbguard-daemon.conf"
# Clean up after ourselves.
rm "/etc/usbguard/usbguard-daemon.conf.bak"
Group   Network Time Protocol   Group contains 2 rules

[ref]   The Network Time Protocol is used to manage the system clock over a network. Computer clocks are not very accurate, so time will drift unpredictably on unmanaged systems. Central time protocols can be used both to ensure that time is consistent among a network of systems, and that their time is consistent with the outside world.

If every system on a network reliably reports the same time, then it is much easier to correlate log messages in case of an attack. In addition, a number of cryptographic protocols (such as Kerberos) use timestamps to prevent certain types of attacks. If your network does not have synchronized time, these protocols may be unreliable or even unusable.

Depending on the specifics of the network, global time accuracy may be just as important as local synchronization, or not very important at all. If your network is connected to the Internet, using a public timeserver (or one provided by your enterprise) provides globally accurate timestamps which may be essential in investigating or responding to an attack which originated outside of your network.

A typical network setup involves a small number of internal systems operating as NTP servers, and the remainder obtaining time information from those internal servers.

There is a choice between the daemons ntpd and chronyd, which are available from the repositories in the ntp and chrony packages respectively.

The default chronyd daemon can work well when external time references are only intermittently accesible, can perform well even when the network is congested for longer periods of time, can usually synchronize the clock faster and with better time accuracy, and quickly adapts to sudden changes in the rate of the clock, for example, due to changes in the temperature of the crystal oscillator. Chronyd should be considered for all systems which are frequently suspended or otherwise intermittently disconnected and reconnected to a network. Mobile and virtual systems for example.

The ntpd NTP daemon fully supports NTP protocol version 4 (RFC 5905), including broadcast, multicast, manycast clients and servers, and the orphan mode. It also supports extra authentication schemes based on public-key cryptography (RFC 5906). The NTP daemon (ntpd) should be considered for systems which are normally kept permanently on. Systems which are required to use broadcast or multicast IP, or to perform authentication of packets with the Autokey protocol, should consider using ntpd.

Refer to https://docs.fedoraproject.org/en-US/fedora/rawhide/system-administrators-guide/servers/Configuring_NTP_Using_the_chrony_Suite/ for more detailed comparison of features of chronyd and ntpd daemon features respectively, and for further guidance how to choose between the two NTP daemons.

The upstream manual pages at http://chrony.tuxfamily.org/manual.html for chronyd and http://www.ntp.org for ntpd provide additional information on the capabilities and configuration of each of the NTP daemons.

Rule   Disable chrony daemon from acting as server   [ref]

The port option in /etc/chrony.conf can be set to 0 to make chrony daemon to never open any listening port for server operation and to operate strictly in a client-only mode.

Rationale:

Minimizing the exposure of the server functionality of the chrony daemon diminishes the attack surface.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_client_only
Identifiers and References

Identifiers:  CCE-82988-7

References:  FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050



# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append /etc/chrony.conf '^port' 0 'CCE-82988-7' '%s %s'


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,cmdport%200%0Apool%200%0A
        filesystem: root
        mode: 0644
        path: /etc/chrony.conf 

Rule   Disable network management of chrony daemon   [ref]

The cmdport option in /etc/chrony.conf can be set to 0 to stop chrony daemon from listening on the UDP port 323 for management connections made by chronyc.

Rationale:

Not exposing the management interface of the chrony daemon on the network diminishes the attack space.

Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_no_chronyc_network
Identifiers and References

Identifiers:  CCE-82840-0

References:  FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050



# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # Strip any search characters in the key arg so that the key can be replaced without
  # adding any search characters to the config file.
  stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$value"

  # If the key exists, change it. Otherwise, add it to the config_file.
  # We search for the key string followed by a word boundary (matched by \>),
  # so if we search for 'setting', 'setting2' won't match.
  if LC_ALL=C grep -q -m 1 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append /etc/chrony.conf '^cmdport' 0 'CCE-82840-0' '%s %s'


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:,cmdport%200%0Apool%200%0A
        filesystem: root
        mode: 0644
        path: /etc/chrony.conf
Group   Kerberos   Group contains 1 rule

[ref]   The Kerberos protocol is used for authentication across non-secure network. Authentication can happen between various types of principals -- users, service, or hosts. Their identity and encryption keys can be stored in keytab files.

Rule   Disable Kerberos by removing host keytab   [ref]

Kerberos is not an approved key distribution method for Common Criteria. To prevent using Kerberos by system daemons, remove the Kerberos keytab files, especially /etc/krb5.keytab.

Rationale:

The key derivation function (KDF) in Kerberos is not FIPS compatible.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kerberos_disable_no_keytab
Identifiers and References

Identifiers:  CCE-82175-1

References:  FCS_CKM.1, SRG-OS-000120-GPOS-00061




rm -f /etc/*.keytab
Group   NFS and RPC   Group contains 1 rule

[ref]   The Network File System is a popular distributed filesystem for the Unix environment, and is very widely deployed. This section discusses the circumstances under which it is possible to disable NFS and its dependencies, and then details steps which should be taken to secure NFS's configuration. This section is relevant to systems operating as NFS clients, as well as to those operating as NFS servers.

Rule   Uninstall nfs-utils Package   [ref]

The nfs-utils package can be removed with the following command:

$ sudo yum erase nfs-utils

Rationale:

nfs-utils provides a daemon for the kernel NFS server and related tools. This package also contains the showmount program. showmount queries the mount daemon on a remote host for information about the Network File System (NFS) server on the remote host. For example, showmount can display the clients which are mounted on that host.

Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_nfs-utils_removed
Identifiers and References

Identifiers:  CCE-82932-5

References:  SRG-OS-000095-GPOS-00049



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove nfs-utils
#	   from the system, and may remove any packages
#	   that depend on nfs-utils. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "nfs-utils" ; then
    yum remove -y "nfs-utils"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure nfs-utils is removed
  package:
    name: nfs-utils
    state: absent
  tags:
    - CCE-82932-5
    - disable_strategy
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - package_nfs-utils_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_nfs-utils

class remove_nfs-utils {
  package { 'nfs-utils':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=nfs-utils
Group   Mail Server Software   Group contains 1 rule

[ref]   Mail servers are used to send and receive email over the network. Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious targets of network attack. Ensure that systems are not running MTAs unnecessarily, and configure needed MTAs as defensively as possible.

Very few systems at any site should be configured to directly receive email over the network. Users should instead use mail client programs to retrieve email from a central server that supports protocols such as IMAP or POP3. However, it is normal for most systems to be independently capable of sending email, for instance so that cron jobs can report output to an administrator. Most MTAs, including Postfix, support a submission-only mode in which mail can be sent from the local system to a central site MTA (or directly delivered to a local account), but the system still cannot receive mail directly over a network.

The alternatives program in Red Hat Enterprise Linux 8 permits selection of other mail server software (such as Sendmail), but Postfix is the default and is preferred. Postfix was coded with security in mind and can also be more effectively contained by SELinux as its modular design has resulted in separate processes performing specific actions. More information is available on its website, http://www.postfix.org.

Rule   Uninstall Sendmail Package   [ref]

Sendmail is not the default mail transfer agent and is not installed by default. The sendmail package can be removed with the following command:

$ sudo yum erase sendmail

Rationale:

The sendmail software was not developed with security in mind and its design prevents it from being effectively contained by SELinux. Postfix should be used instead.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_sendmail_removed
Identifiers and References

Identifiers:  CCE-81039-0

References:  NT28(R1), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove sendmail
#	   from the system, and may remove any packages
#	   that depend on sendmail. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "sendmail" ; then
    yum remove -y "sendmail"
fi


Complexity:low
Disruption:low
Strategy:disable
- name: Ensure sendmail is removed
  package:
    name: sendmail
    state: absent
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-81039-0
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-7(a)
    - NIST-800-53-CM-7(b)
    - disable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - package_sendmail_removed


Complexity:low
Disruption:low
Strategy:disable
include remove_sendmail

class remove_sendmail {
  package { 'sendmail':
    ensure => 'purged',
  }
}


Complexity:low
Disruption:low
Strategy:disable

package --remove=sendmail
Group   Hardware RNG Entropy Gatherer Daemon   Group contains 1 rule

[ref]   The rngd feeds random data from hardware device to kernel random device.

Rule   Enable the Hardware RNG Entropy Gatherer Service   [ref]

The Hardware RNG Entropy Gatherer service should be enabled. The rngd service can be enabled with the following command:

$ sudo systemctl enable rngd.service

Rationale:

The rngd service feeds random data from hardware device to kernel random device.

Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_rngd_enabled
Identifiers and References

Identifiers:  CCE-82831-9

References:  FCS_RBG_EXT.1, SRG-OS-000480-GPOS-00227



Complexity:low
Disruption:low
Strategy:enable

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" start 'rngd.service'
"$SYSTEMCTL_EXEC" enable 'rngd.service'


Complexity:low
Disruption:low
Strategy:enable
- name: Enable service rngd
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable service rngd
      service:
        name: rngd
        enabled: 'yes'
        state: started
      when:
        - '"rng-tools" in ansible_facts.packages'
  when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"
  tags:
    - CCE-82831-9
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_rngd_enabled


Complexity:low
Disruption:low
Strategy:enable
include enable_rngd

class enable_rngd {
  service {'rngd':
    enable => true,
    ensure => 'running',
  }
}
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