Guide to the Secure Configuration of SUSE Linux Enterprise 15

with profile Public Cloud Hardening for SUSE Linux Enterprise 15
This profile contains configuration checks to be used to harden SUSE Linux Enterprise 15 for use with public cloud providers.
This guide presents a catalog of security-relevant configuration settings for SUSE Linux Enterprise 15. 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 TitlePublic Cloud Hardening for SUSE Linux Enterprise 15
Profile IDxccdf_org.ssgproject.content_profile_pcs-hardening

CPE Platforms

  • cpe:/o:suse:linux_enterprise_desktop:15
  • cpe:/o:suse:linux_enterprise_server:15

Revision History

Current version: 0.1.74

  • draft (as of 2024-07-17)

Table of Contents

  1. System Settings
    1. Installing and Maintaining Software
    2. Account and Access Control
    3. Configure Syslog
    4. Network Configuration and Firewalls
    5. File Permissions and Masks
  2. Services
    1. Cron and At Daemons
    2. Network Time Protocol
    3. SSH Server
  3. System Accounting with auditd
    1. Configure auditd Rules for Comprehensive Auditing
    2. Configure auditd Data Retention

Checklist

Group   Guide to the Secure Configuration of SUSE Linux Enterprise 15   Group contains 51 groups and 162 rules
Group   System Settings   Group contains 33 groups and 50 rules
[ref]   Contains rules that check correct system settings.
Group   Installing and Maintaining Software   Group contains 5 groups and 7 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 2 groups and 4 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 4 rules
[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 4 rules
[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   Configure AIDE to Verify the Audit Tools   [ref]

The operating system file integrity tool must be configured to protect the integrity of the audit tools.
Rationale:
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include but are not limited to vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_aide_check_audit_tools
Identifiers:

CCE-85610-4

References:
disaCCI-001496
nistAU-9(3), AU-9(3).1
os-srgSRG-OS-000278-GPOS-00108
stigidSLES-15-030630
stigrefSV-234962r877393_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Configure AIDE to Verify the Audit Tools - Gather List of Packages
  tags:
  - CCE-85610-4
  - DISA-STIG-SLES-15-030630
  - NIST-800-53-AU-9(3)
  - NIST-800-53-AU-9(3).1
  - aide_check_audit_tools
  - aide_check_audit_tools
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  ansible.builtin.package_facts:
    manager: auto
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]

- name: Ensure aide is installed
  package:
    name: '{{ item }}'
    state: present
  with_items:
  - aide
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85610-4
  - DISA-STIG-SLES-15-030630
  - NIST-800-53-AU-9(3)
  - NIST-800-53-AU-9(3).1
  - aide_check_audit_tools
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set audit_tools fact
  set_fact:
    audit_tools:
    - /usr/sbin/audispd
    - /usr/sbin/auditctl
    - /usr/sbin/auditd
    - /usr/sbin/augenrules
    - /usr/sbin/aureport
    - /usr/sbin/ausearch
    - /usr/sbin/autrace
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85610-4
  - DISA-STIG-SLES-15-030630
  - NIST-800-53-AU-9(3)
  - NIST-800-53-AU-9(3).1
  - aide_check_audit_tools
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure existing AIDE configuration for audit tools are correct
  lineinfile:
    path: /etc/aide.conf
    regexp: ^{{ item }}\s
    line: '{{ item }} p+i+n+u+g+s+b+acl+selinux+xattrs+sha512'
  with_items: '{{ audit_tools }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85610-4
  - DISA-STIG-SLES-15-030630
  - NIST-800-53-AU-9(3)
  - NIST-800-53-AU-9(3).1
  - aide_check_audit_tools
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure AIDE to properly protect audit tools
  lineinfile:
    path: /etc/aide.conf
    line: '{{ item }} p+i+n+u+g+s+b+acl+selinux+xattrs+sha512'
  with_items: '{{ audit_tools }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85610-4
  - DISA-STIG-SLES-15-030630
  - NIST-800-53-AU-9(3)
  - NIST-800-53-AU-9(3).1
  - aide_check_audit_tools
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

zypper install -y "aide"










if grep -i '^.*/usr/sbin/auditctl.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/auditctl.*#/usr/sbin/auditctl p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/auditctl p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

if grep -i '^.*/usr/sbin/auditd.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/auditd.*#/usr/sbin/auditd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/auditd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

if grep -i '^.*/usr/sbin/ausearch.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/ausearch.*#/usr/sbin/ausearch p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/ausearch p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

if grep -i '^.*/usr/sbin/aureport.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/aureport.*#/usr/sbin/aureport p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/aureport p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

if grep -i '^.*/usr/sbin/autrace.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/autrace.*#/usr/sbin/autrace p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/autrace p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

if grep -i '^.*/usr/sbin/augenrules.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/augenrules.*#/usr/sbin/augenrules p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/augenrules p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

if grep -i '^.*/usr/sbin/audispd.*$' /etc/aide.conf; then
sed -i "s#.*/usr/sbin/audispd.*#/usr/sbin/audispd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/audispd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure Systemd Timer Execution of AIDE   [ref]

At a minimum, AIDE should be configured to run a weekly scan. To implement a systemd service and a timer unit to run the service periodically: For example, if a systemd timer is expected to be started every day at 5AM
OnCalendar=*-*-* 05:00:0
[Timer]
section in the timer unit and a Unit section starting the AIDE check service unit should be referred.
Rationale:
AIDE provides a means to check if unauthorized changes are made to the system. AIDE itself does not setup a periodic execution, so in order to detect unauthorized changes a systemd service to run the check and a systemd timer to take care of periodical execution of that systemd service should be defined.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_aide_periodic_checking_systemd_timer
Identifiers:

CCE-92516-4

References:
cis-csc1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9
cjis5.10.1.3
cobit5APO01.06, 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
disaCCI-001744, CCI-002699, CCI-002702
isa-62443-20094.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4
isa-62443-2013SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6
iso27001-2013A.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
nistSI-6(d)
nist-csfDE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3
pcidssReq-11.5
os-srgSRG-OS-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201
stigidSLES-15-010570
cis1.4.2
anssiR76
pcidss411.5.2
stigrefSV-234864r902854_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-92516-4
  - CJIS-5.10.1.3
  - DISA-STIG-SLES-15-010570
  - NIST-800-53-SI-6(d)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_checking_systemd_timer
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure Systemd Timer Execution of AIDE - Define AIDE Periodic Check Service
  ansible.builtin.blockinfile:
    create: true
    dest: /etc/systemd/system/aidecheck.service
    owner: root
    group: root
    mode: '0644'
    block: |
      [Unit]
      Description=Aide Check
      [Service]
      Type=simple
      ExecStart=/usr/bin/aide --check
      [Install]
      WantedBy=multi-user.target
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"aide" in ansible_facts.packages'
  tags:
  - CCE-92516-4
  - CJIS-5.10.1.3
  - DISA-STIG-SLES-15-010570
  - NIST-800-53-SI-6(d)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_checking_systemd_timer
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure Systemd Timer Execution of AIDE - Define AIDE Periodic Check Service
    Timer
  ansible.builtin.blockinfile:
    create: true
    dest: /etc/systemd/system/aidecheck.timer
    owner: root
    group: root
    mode: '0644'
    block: |
      [Unit]
      Description=Aide check every day at 5AM
      [Timer]
      OnCalendar=*-*-* 05:00:00
      Unit=aidecheck.service
      [Install]
      WantedBy=multi-user.target
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"aide" in ansible_facts.packages'
  tags:
  - CCE-92516-4
  - CJIS-5.10.1.3
  - DISA-STIG-SLES-15-010570
  - NIST-800-53-SI-6(d)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_checking_systemd_timer
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure Systemd Timer Execution of AIDE - Ensure AIDE Service is Enabled
  ansible.builtin.systemd:
    name: aidecheck.service
    enabled: true
    daemon_reload: true
    masked: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"aide" in ansible_facts.packages'
  tags:
  - CCE-92516-4
  - CJIS-5.10.1.3
  - DISA-STIG-SLES-15-010570
  - NIST-800-53-SI-6(d)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_checking_systemd_timer
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure Systemd Timer Execution of AIDE - Ensure AIDE Service Timer is Enabled
  ansible.builtin.systemd:
    name: aidecheck.timer
    state: started
    enabled: true
    daemon_reload: true
    masked: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"aide" in ansible_facts.packages'
  tags:
  - CCE-92516-4
  - CJIS-5.10.1.3
  - DISA-STIG-SLES-15-010570
  - NIST-800-53-SI-6(d)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_checking_systemd_timer
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q aide; }; then

zypper install -y "aide"

# create unit file for periodic aide database check
cat > /etc/systemd/system/aidecheck.service <<EOF
[Unit]
Description=Aide Check
[Service]
Type=simple
ExecStart=/usr/bin/aide --check
[Install]
WantedBy=multi-user.target
EOF

# create unit file for the aide check timer
cat > /etc/systemd/system/aidecheck.timer <<EOF
[Unit]
Description=Aide check every day at 5AM
[Timer]
OnCalendar=*-*-* 05:00:00
Unit=aidecheck.service
[Install]
WantedBy=multi-user.target
EOF

#  setup service unit files attributes
chown root:root /etc/systemd/system/aidecheck.*
chmod 0644 /etc/systemd/system/aidecheck.*

# enable the aide related services
systemctl daemon-reload
systemctl enable aidecheck.service
systemctl --now enable aidecheck.timer

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure AIDE to Verify Access Control Lists (ACLs)   [ref]

By default, the acl option is added to the FIPSR ruleset in AIDE. If using a custom ruleset or the acl option is missing, add acl to the appropriate ruleset. For example, add acl to the following line in /etc/aide.conf:
FIPSR = p+i+n+u+g+s+m+c+acl+selinux+xattrs+sha256
AIDE rules can be configured in multiple ways; this is merely one example that is already configured by default. The remediation provided with this rule adds acl to all rule sets available in /etc/aide.conf
Rationale:
ACLs can provide permissions beyond those permitted through the file mode and must be verified by the file integrity tools.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_aide_verify_acls
Identifiers:

CCE-85623-7

References:
cis-csc2, 3
cobit5APO01.06, BAI03.05, BAI06.01, DSS06.02
disaCCI-000366
isa-62443-20094.3.4.4.4
isa-62443-2013SR 3.1, SR 3.3, SR 3.4, SR 3.8
iso27001-2013A.11.2.4, A.12.2.1, A.12.5.1, A.14.1.2, A.14.1.3, A.14.2.4
nistSI-7, SI-7(1), CM-6(a)
nist-csfPR.DS-6, PR.DS-8
os-srgSRG-OS-000480-GPOS-00227
stigidSLES-15-040040
anssiR76
stigrefSV-234986r880968_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather list of packages
  package_facts:
    manager: auto
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ''
  tags:
  - CCE-85623-7
  - DISA-STIG-SLES-15-040040
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - aide_verify_acls
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

- name: Get rules groups
  shell: |
    set -o pipefail
    LC_ALL=C grep "^[A-Z][A-Za-z_]*" /etc/aide.conf | grep -v "^ALLXTRAHASHES" | cut -f1 -d '=' | tr -d ' ' | sort -u || true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '''aide'' in ansible_facts.packages'
  register: find_rules_groups_results
  tags:
  - CCE-85623-7
  - DISA-STIG-SLES-15-040040
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - aide_verify_acls
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the acl rule is present when aide is installed.
  replace:
    path: /etc/aide.conf
    regexp: (^\s*{{ item }}\s*=\s*)(?!.*acl)([^\s]*)
    replace: \g<1>\g<2>+acl
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_rules_groups_results is not skipped and "'aide' in ansible_facts.packages"
  with_items: '{{ find_rules_groups_results.stdout_lines | map(''trim'') | list }}'
  tags:
  - CCE-85623-7
  - DISA-STIG-SLES-15-040040
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - aide_verify_acls
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

zypper install -y "aide"

aide_conf="/etc/aide.conf"

groups=$(LC_ALL=C grep "^[A-Z][A-Za-z_]*" $aide_conf | grep -v "^ALLXTRAHASHES" | cut -f1 -d '=' | tr -d ' ' | sort -u)

for group in $groups
do
	config=$(grep "^$group\s*=" $aide_conf | cut -f2 -d '=' | tr -d ' ')

	if ! [[ $config = *acl* ]]
	then
		if [[ -z $config ]]
		then
			config="acl"
		else
			config=$config"+acl"
		fi
	fi
	sed -i "s/^$group\s*=.*/$group = $config/g" $aide_conf
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure AIDE to Verify Extended Attributes   [ref]

By default, the xattrs option is added to the FIPSR ruleset in AIDE. If using a custom ruleset or the xattrs option is missing, add xattrs to the appropriate ruleset. For example, add xattrs to the following line in /etc/aide.conf:
FIPSR = p+i+n+u+g+s+m+c+acl+selinux+xattrs+sha256
AIDE rules can be configured in multiple ways; this is merely one example that is already configured by default. The remediation provided with this rule adds xattrs to all rule sets available in /etc/aide.conf
Rationale:
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_aide_verify_ext_attributes
Identifiers:

CCE-85624-5

References:
cis-csc2, 3
cobit5APO01.06, BAI03.05, BAI06.01, DSS06.02
disaCCI-000366
isa-62443-20094.3.4.4.4
isa-62443-2013SR 3.1, SR 3.3, SR 3.4, SR 3.8
iso27001-2013A.11.2.4, A.12.2.1, A.12.5.1, A.14.1.2, A.14.1.3, A.14.2.4
nistSI-7, SI-7(1), CM-6(a)
nist-csfPR.DS-6, PR.DS-8
os-srgSRG-OS-000480-GPOS-00227
stigidSLES-15-040050
anssiR76
stigrefSV-234987r880969_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather list of packages
  package_facts:
    manager: auto
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ''
  tags:
  - CCE-85624-5
  - DISA-STIG-SLES-15-040050
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - aide_verify_ext_attributes
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

- name: Get rules groups
  shell: |
    set -o pipefail
    LC_ALL=C grep "^[A-Z][A-Za-z_]*" /etc/aide.conf | grep -v "^ALLXTRAHASHES" | cut -f1 -d '=' | tr -d ' ' | sort -u || true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '''aide'' in ansible_facts.packages'
  register: find_rules_groups_results
  tags:
  - CCE-85624-5
  - DISA-STIG-SLES-15-040050
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - aide_verify_ext_attributes
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the xattrs rule is present when aide is installed.
  replace:
    path: /etc/aide.conf
    regexp: (^\s*{{ item }}\s*=\s*)(?!.*xattrs)([^\s]*)
    replace: \g<1>\g<2>+xattrs
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_rules_groups_results is not skipped and "'aide' in ansible_facts.packages"
  with_items: '{{ find_rules_groups_results.stdout_lines | map(''trim'') | list }}'
  tags:
  - CCE-85624-5
  - DISA-STIG-SLES-15-040050
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - aide_verify_ext_attributes
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

zypper install -y "aide"

aide_conf="/etc/aide.conf"

groups=$(LC_ALL=C grep "^[A-Z][A-Za-z_]*" $aide_conf | grep -v "^ALLXTRAHASHES" | cut -f1 -d '=' | tr -d ' ' | sort -u)

for group in $groups
do
	config=$(grep "^$group\s*=" $aide_conf | cut -f2 -d '=' | tr -d ' ')

	if ! [[ $config = *xattrs* ]]
	then
		if [[ -z $config ]]
		then
			config="xattrs"
		else
			config=$config"+xattrs"
		fi
	fi
	sed -i "s/^$group\s*=.*/$group = $config/g" $aide_conf
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Sudo   Group contains 2 rules
[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   Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty   [ref]

The sudo use_pty tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by making sure that the use_pty tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
Requiring that sudo commands be run in a pseudo-terminal can prevent an attacker from retaining access to the user's terminal after the main program has finished executing.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_use_pty
Identifiers:

CCE-91190-9

References:
pcidssReq-10.2.5
cis1.3.2
anssiR39
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-91190-9
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_use_pty

- name: Ensure use_pty is enabled in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults.*\buse_pty\b.*$
    line: Defaults use_pty
    validate: /usr/sbin/visudo -cf %s
  when: '"sudo" in ansible_facts.packages'
  tags:
  - CCE-91190-9
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_use_pty

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q sudo; then

if /usr/sbin/visudo -qcf /etc/sudoers; then
    cp /etc/sudoers /etc/sudoers.bak
    if ! grep -P '^[\s]*Defaults[\s]*\buse_pty\b.*$' /etc/sudoers; then
        # sudoers file doesn't define Option use_pty
        echo "Defaults use_pty" >> /etc/sudoers
    fi
    
    # Check validity of sudoers and cleanup bak
    if /usr/sbin/visudo -qcf /etc/sudoers; then
        rm -f /etc/sudoers.bak
    else
        echo "Fail to validate remediated /etc/sudoers, reverting to original file."
        mv /etc/sudoers.bak /etc/sudoers
        false
    fi
else
    echo "Skipping remediation, /etc/sudoers failed to validate"
    false
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure Sudo Logfile Exists - sudo logfile   [ref]

A custom log sudo file can be configured with the 'logfile' tag. This rule configures a sudo custom logfile at the default location suggested by CIS, which uses /var/log/sudo.log.
Rationale:
A sudo log file simplifies auditing of sudo commands.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_sudo_custom_logfile
Identifiers:

CCE-91311-1

References:
pcidssReq-10.2.5
cis1.3.3
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-91311-1
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_custom_logfile
- name: XCCDF Value var_sudo_logfile # promote to variable
  set_fact:
    var_sudo_logfile: !!str /var/log/sudo.log
  tags:
    - always

- name: Ensure logfile is enabled with the appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults\s(.*)\blogfile=[-]?.+\b(.*)$
    line: Defaults \1logfile={{ var_sudo_logfile }}\2
    validate: /usr/sbin/visudo -cf %s
    backrefs: true
  register: edit_sudoers_logfile_option
  when: '"sudo" in ansible_facts.packages'
  tags:
  - CCE-91311-1
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_custom_logfile

- name: Enable logfile option with appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    line: Defaults logfile={{ var_sudo_logfile }}
    validate: /usr/sbin/visudo -cf %s
  when:
  - '"sudo" in ansible_facts.packages'
  - edit_sudoers_logfile_option is defined and not edit_sudoers_logfile_option.changed
  tags:
  - CCE-91311-1
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_custom_logfile

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q sudo; then

var_sudo_logfile='/var/log/sudo.log'


if /usr/sbin/visudo -qcf /etc/sudoers; then
    cp /etc/sudoers /etc/sudoers.bak
    if ! grep -P '^[\s]*Defaults[\s]*\blogfile\s*=\s*(?:"?([^",\s]+)"?)\b.*$' /etc/sudoers; then
        # sudoers file doesn't define Option logfile
        echo "Defaults logfile=${var_sudo_logfile}" >> /etc/sudoers
    else
        # sudoers file defines Option logfile, remediate if appropriate value is not set
        if ! grep -P "^[\s]*Defaults.*\blogfile=${var_sudo_logfile}\b.*$" /etc/sudoers; then
            
            escaped_variable=${var_sudo_logfile//$'/'/$'\/'}
            sed -Ei "s/(^[\s]*Defaults.*\blogfile=)[-]?.+(\b.*$)/\1$escaped_variable\2/" /etc/sudoers
        fi
    fi
    
    # Check validity of sudoers and cleanup bak
    if /usr/sbin/visudo -qcf /etc/sudoers; then
        rm -f /etc/sudoers.bak
    else
        echo "Fail to validate remediated /etc/sudoers, reverting to original file."
        mv /etc/sudoers.bak /etc/sudoers
        false
    fi
else
    echo "Skipping remediation, /etc/sudoers failed to validate"
    false
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Updating Software   Group contains 1 rule
[ref]   The zypper 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.

SUSE Linux Enterprise 15 systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using zypper or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.

Rule   Ensure gpgcheck Enabled In Main zypper Configuration   [ref]

The gpgcheck option controls whether RPM packages' signatures are always checked prior to installation. To configure zypper to check package signatures before installing them, ensure the following line appears in /etc/zypp/zypp.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:

CCE-83290-7

References:
cis-csc11, 2, 3, 9
cjis5.10.4.1
cobit5APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02
cui3.4.8
disaCCI-001749
hipaa164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i)
isa-62443-20094.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4
isa-62443-2013SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6
iso27001-2013A.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
nistCM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b)
nist-csfPR.DS-6, PR.DS-8, PR.IP-1
osppFPT_TUD_EXT.1, FPT_TUD_EXT.2
pcidssReq-6.2
os-srgSRG-OS-000366-GPOS-00153
stigidSLES-15-010430
cis1.2.3
anssiR59
pcidss46.3.3
stigrefSV-234852r877463_rule

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-83290-7
  - CJIS-5.10.4.1
  - DISA-STIG-SLES-15-010430
  - 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
  - PCI-DSSv4-6.3.3
  - configure_strategy
  - ensure_gpgcheck_globally_activated
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed

- name: Ensure GPG check is globally activated
  ini_file:
    dest: /etc/zypp/zypp.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when: '"zypper" in ansible_facts.packages'
  tags:
  - CCE-83290-7
  - CJIS-5.10.4.1
  - DISA-STIG-SLES-15-010430
  - 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
  - PCI-DSSv4-6.3.3
  - configure_strategy
  - ensure_gpgcheck_globally_activated
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if rpm --quiet -q zypper; then

# 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' <<< "^gpgcheck")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

# 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 -i -e "^gpgcheck\\>" "/etc/zypp/zypp.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^gpgcheck\\>.*/$escaped_formatted_output/gi" "/etc/zypp/zypp.conf"
else
    if [[ -s "/etc/zypp/zypp.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/zypp/zypp.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/zypp/zypp.conf"
    fi
    cce="CCE-83290-7"
    printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/zypp/zypp.conf" >> "/etc/zypp/zypp.conf"
    printf '%s\n' "$formatted_output" >> "/etc/zypp/zypp.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Account and Access Control   Group contains 15 groups and 31 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 SUSE Linux Enterprise 15.
Group   Warning Banners for System Accesses   Group contains 4 rules
[ref]   Each system should expose as little information about itself as possible.

System banners, which are typically displayed just before a login prompt, give out information about the service or the host's operating system. This might include the distribution name and the system kernel version, and the particular version of a network service. This information can assist intruders in gaining access to the system as it can reveal whether the system is running vulnerable software. Most network services can be configured to limit what information is displayed.

Many organizations implement security policies that require a system banner provide notice of the system's ownership, provide warning to unauthorized users, and remind authorized users of their consent to monitoring.

Rule   Modify the System Login Banner   [ref]

To configure the system login banner edit /etc/issue. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.
Rationale:
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_banner_etc_issue
Identifiers:

CCE-83262-6

References:
cis-csc1, 12, 15, 16
cobit5DSS05.04, DSS05.10, DSS06.10
cui3.1.9
disaCCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388
isa-62443-20094.3.3.6.1, 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
isa-62443-2013SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nistAC-8(a), AC-8(c)
nist-csfPR.AC-7
osppFMT_MOF_EXT.1
os-srgSRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
stigidSLES-15-010020
cis1.8.1.2
stigrefSV-234803r951623_rule

Complexity:low
Disruption:medium
Reboot:false
Strategy:unknown
- name: XCCDF Value login_banner_text # promote to variable
  set_fact:
    login_banner_text: !!str ^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
  tags:
    - always

- name: Modify the System Login Banner Ensure issue-generator is Installed
  package:
    name: issue-generator
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020
  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Modify the System Login Banner - Ensure Correct Banner
  copy:
    dest: /etc/issue.d/99-oscap-setting
    content: '{{ login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
      "\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
      "\n") | regex_replace("\\", "") | wordwrap() }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020
  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Modify the System Login Banner Retart issue-generator Service on Issue Configration
    Change
  ansible.builtin.systemd:
    name: issue-generator
    enabled: 'yes'
    state: restarted
    masked: 'no'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020
  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

login_banner_text='^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'


# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
login_banner_text=$(echo "$login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
#    (dod_banners contains the long and short banner)
login_banner_text=$(echo "$login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
login_banner_text=$(echo "$login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
login_banner_text=$(echo "$login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parethesis in the banner, for example).
login_banner_text=$(echo "$login_banner_text" | sed 's/\\//g')
formatted=$(echo "$login_banner_text" | fold -sw 80)
zypper install -y "issue-generator"
cat <<EOF >/etc/issue.d/99-oscap-setting
$formatted
EOF
/usr/bin/systemctl enable "issue-generator"
/usr/bin/systemctl start "issue-generator"
# 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.
if /usr/bin/systemctl --failed | grep -q "issue-generator"; then
    /usr/bin/systemctl reset-failed "issue-generator"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Modify the System Message of the Day Banner   [ref]

To configure the system message banner edit /etc/motd. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.
Rationale:
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_banner_etc_motd
Identifiers:

CCE-91349-1

References:
cis1.8.1.1

Complexity:low
Disruption:medium
Reboot:false
Strategy:unknown
- name: XCCDF Value motd_banner_text # promote to variable
  set_fact:
    motd_banner_text: !!str ^Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.$
  tags:
    - always

- name: Modify the System Message of the Day Banner - ensure correct banner
  copy:
    dest: /etc/motd
    content: '{{ motd_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
      "\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
      "\n") | regex_replace("\\", "") | wordwrap() }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91349-1
  - banner_etc_motd
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

motd_banner_text='^Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.$'


# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
motd_banner_text=$(echo "$motd_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
#    (dod_banners contains the long and short banner)
motd_banner_text=$(echo "$motd_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
motd_banner_text=$(echo "$motd_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
motd_banner_text=$(echo "$motd_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parethesis in the banner, for example).
motd_banner_text=$(echo "$motd_banner_text" | sed 's/\\//g')
formatted=$(echo "$motd_banner_text" | fold -sw 80)

cat <<EOF >/etc/motd
$formatted
EOF

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Ownership of System Login Banner   [ref]

To properly set the group owner of /etc/issue, run the command:
$ sudo chgrp root /etc/issue
Rationale:
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_issue
Identifiers:

CCE-91355-8

References:
cis1.8.1.5

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/issue.d/ file(s) matching ^.*$ recursively
  command: find -H /etc/issue.d/  -type f ! -group 0 -regextype posix-extended -regex
    "^.*$"
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  tags:
  - CCE-91355-8
  - configure_strategy
  - file_groupowner_etc_issue
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner on /etc/issue.d/ file(s) matching ^.*$
  file:
    path: '{{ item }}'
    group: '0'
    state: file
  with_items:
  - '{{ files_found.stdout_lines }}'
  tags:
  - CCE-91355-8
  - configure_strategy
  - file_groupowner_etc_issue
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure

find /etc/issue.d/  -type f ! -group 0 -regextype posix-extended -regex '^.*$' -exec chgrp 0 {} \;

Rule   Verify ownership of System Login Banner   [ref]

To properly set the owner of /etc/issue, run the command:
$ sudo chown root /etc/issue 
Rationale:
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_issue
Identifiers:

CCE-91356-6

References:
cis1.8.1.5

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/issue.d/ file(s) matching ^.*$ recursively
  command: find -H /etc/issue.d/  -type f ! -uid 0 -regextype posix-extended -regex
    "^.*$"
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  tags:
  - CCE-91356-6
  - configure_strategy
  - file_owner_etc_issue
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner on /etc/issue.d/ file(s) matching ^.*$
  file:
    path: '{{ item }}'
    owner: '0'
    state: file
  with_items:
  - '{{ files_found.stdout_lines }}'
  tags:
  - CCE-91356-6
  - configure_strategy
  - file_owner_etc_issue
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure

find /etc/issue.d/  -type f ! -uid 0 -regextype posix-extended -regex '^.*$' -exec chown 0 {} \;
Group   Protect Accounts by Configuring PAM   Group contains 4 groups and 13 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 https://fossies.org/linux/Linux-PAM-docs/doc/sag/Linux-PAM_SAG.pdf.
Group   Set Lockouts for Failed Password Attempts   Group contains 3 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_pwhistory PAM modules.

In the file /etc/pam.d/common-password, make sure the parameters remember and use_authtok are present, and that the value for the remember parameter is 5 or greater. For example:
password requisite pam_pwhistory.so ...existing_options... remember=5 use_authtok
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_pwhistory_remember
Identifiers:

CCE-91398-8

References:
disaCCI-000200
os-srgSRG-OS-000077-GPOS-00045
cis5.3.3

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_remember # promote to variable
  set_fact:
    var_password_pam_remember: !!str 5
  tags:
    - always

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_pwhistory.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_pwhistory.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_pwhistory.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_pwhistory.so
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_result.stdout is defined and '"pam_pwhistory.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_pwhistory.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_pwhistory.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - control_flag|length
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_pwhistory.so" module has argument "remember={{ var_password_pam_remember
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so(?:\s+\S+)*\s+remember=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_remember }}\g<2>
    backrefs: true
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "remember" argument in "pam_pwhistory.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_pwhistory.so.*\s+remember(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "remember" argument to "pam_pwhistory.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> remember={{ var_password_pam_remember }}\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_argument_result is not skipped and '"remember" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set argument_value fact
  set_fact:
    argument_value: ''
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_pwhistory.so" module has argument "use_authtok"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so(?:\s+\S+)*\s+use_authtok=)(?!)\S*((\s+\S+)*\s*\\*\s*)$
    line: \g<1>\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - argument_value|length
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "use_authtok" argument in "pam_pwhistory.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_pwhistory.so.*\s+use_authtok(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "use_authtok" argument to "pam_pwhistory.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> use_authtok\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_argument_result is not skipped and '"use_authtok" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-91398-8
  - accounts_password_pam_pwhistory_remember
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_remember='5'

VALUES+=("$var_password_pam_remember")
VALUE_NAMES+=("remember")
ARGS+=("")
NEW_ARGS+=("")
VALUES+=("")
VALUE_NAMES+=("")
ARGS+=("use_authtok")
NEW_ARGS+=("use_authtok")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_pwhistory.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_pwhistory.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_pwhistory.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_pwhistory.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_pwhistory.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_pwhistory.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_pwhistory.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_pwhistory.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_pwhistory.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enforce Delay After Failed Logon Attempts   [ref]

To configure the system to introduce a delay after failed logon attempts, add or correct the pam_faildelay settings in /etc/pam.d/common-auth to make sure its delay parameter is at least 4000000 or greater. For example:
auth required pam_faildelay.so delay=4000000
         
Rationale:
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faildelay_delay
Identifiers:

CCE-85619-5

References:
disaCCI-000366
os-srgSRG-OS-000480-GPOS-00226
stigidSLES-15-040010
stigrefSV-234983r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_delay # promote to variable
  set_fact:
    var_password_pam_delay: !!str 4000000
  tags:
    - always

- name: Set control_flag fact
  set_fact:
    control_flag: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_faildelay.so' module is configured in '/etc/pam.d/common-auth'
  shell: |
    set -o pipefail
    grep -E '^\s*auth\s+\S+\s+pam_faildelay.so' /etc/pam.d/common-auth || true
  register: check_pam_module_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_faildelay.so' module in '/etc/pam.d/common-auth'
  lineinfile:
    path: /etc/pam.d/common-auth
    line: auth required pam_faildelay.so
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_result.stdout is defined and '"pam_faildelay.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_faildelay.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-auth
    regexp: ^(\s*auth\s+)\S+(\s+pam_faildelay.so\s+.*)
    line: \g<1>required\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - control_flag|length
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_faildelay.so" module has argument "delay={{ var_password_pam_delay
    }}"
  lineinfile:
    path: /etc/pam.d/common-auth
    regexp: ^(\s*auth\s+required\s+pam_faildelay.so(?:\s+\S+)*\s+delay=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_delay }}\g<2>
    backrefs: true
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "delay" argument in "pam_faildelay.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*auth\s+required\s+pam_faildelay.so.*\s+delay(=|\s|\s*$)' /etc/pam.d/common-auth || true
  register: check_pam_module_argument_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "delay" argument to "pam_faildelay.so" module
  lineinfile:
    path: /etc/pam.d/common-auth
    regexp: ^(\s*auth\s+required\s+pam_faildelay.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> delay={{ var_password_pam_delay }}\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_argument_result is not skipped and '"delay" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85619-5
  - DISA-STIG-SLES-15-040010
  - accounts_passwords_pam_faildelay_delay
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_delay='4000000'


if [ -e "/etc/pam.d/common-auth" ] ; then
    valueRegex="$var_password_pam_delay" defaultValue="$var_password_pam_delay"
    # non-empty values need to be preceded by an equals sign
    [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
    # add an equals sign to non-empty values
    [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

    # fix 'type' if it's wrong
    if grep -q -P "^\\s*(?"'!'"auth\\s)[[:alnum:]]+\\s+[[:alnum:]]+\\s+pam_faildelay.so" < "/etc/pam.d/common-auth" ; then
        sed --follow-symlinks -i -E -e "s/^(\\s*)[[:alnum:]]+(\\s+[[:alnum:]]+\\s+pam_faildelay.so)/\\1auth\\2/" "/etc/pam.d/common-auth"
    fi

    # fix 'control' if it's wrong
    if grep -q -P "^\\s*auth\\s+(?"'!'"required)[[:alnum:]]+\\s+pam_faildelay.so" < "/etc/pam.d/common-auth" ; then
        sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+)[[:alnum:]]+(\\s+pam_faildelay.so)/\\1required\\2/" "/etc/pam.d/common-auth"
    fi

    # fix the value for 'option' if one exists but does not match 'valueRegex'
    if grep -q -P "^\\s*auth\\s+required\\s+pam_faildelay.so(\\s.+)?\\s+delay(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-auth" ; then
        sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+required\\s+pam_faildelay.so(\\s.+)?\\s)delay=[^[:space:]]*/\\1delay${defaultValue}/" "/etc/pam.d/common-auth"

    # add 'option=default' if option is not set
    elif grep -q -E "^\\s*auth\\s+required\\s+pam_faildelay.so" < "/etc/pam.d/common-auth" &&
            grep    -E "^\\s*auth\\s+required\\s+pam_faildelay.so" < "/etc/pam.d/common-auth" | grep -q -E -v "\\sdelay(=|\\s|\$)" ; then

        sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+required\\s+pam_faildelay.so[^\\n]*)/\\1 delay${defaultValue}/" "/etc/pam.d/common-auth"
    # add a new entry if none exists
    elif ! grep -q -P "^\\s*auth\\s+required\\s+pam_faildelay.so(\\s.+)?\\s+delay${valueRegex}(\\s|\$)" < "/etc/pam.d/common-auth" ; then
        echo "auth required pam_faildelay.so delay${defaultValue}" >> "/etc/pam.d/common-auth"
    fi
else
    echo "/etc/pam.d/common-auth doesn't exist" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set Deny For Failed Password Attempts   [ref]

The SUSE Linux Enterprise 15 operating system must lock an account after - at most - 5 consecutive invalid access attempts.
Rationale:
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. To configure the operating system to lock an account after three unsuccessful consecutive access attempts using pam_tally2.so, modify the content of both /etc/pam.d/login and /etc/pam.d/common-account as follows:

  • add or modify the pam_tally2.so module line in /etc/pam.d/login to ensure both onerr=fail and deny=5 are present. For example:
    auth required pam_tally2.so onerr=fail silent audit deny=5
               
  • add or modify the following line in /etc/pam.d/common-account:
    account required pam_tally2.so
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_tally2
Identifiers:

CCE-85554-4

References:
disaCCI-000044
pcidssReq-8.1.6
os-srgSRG-OS-000021-GPOS-00005
stigidSLES-15-020010
cis5.3.2
anssiR31
pcidss48.3.4
stigrefSV-234867r854212_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_password_pam_tally2 # promote to variable
  set_fact:
    var_password_pam_tally2: !!str 5
  tags:
    - always

- name: Set Deny For Failed Password Attempts - Define a fact for control already
    filtered in case filters are used
  ansible.builtin.set_fact:
    pam_module_control: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Check if expected PAM module line
    is present in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    regexp: ^\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s*.*
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_line_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Include or update the PAM module line
    in /etc/pam.d/login
  block:

  - name: Set Deny For Failed Password Attempts - Check if required PAM module line
      is present in /etc/pam.d/login with different control
    ansible.builtin.lineinfile:
      path: /etc/pam.d/login
      regexp: ^\s*auth\s+.*\s+pam_tally2.so\s*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_other_control_present

  - name: Set Deny For Failed Password Attempts - Ensure the correct control for the
      required PAM module line in /etc/pam.d/login
    ansible.builtin.replace:
      dest: /etc/pam.d/login
      regexp: ^(\s*auth\s+).*(\bpam_tally2.so.*)
      replace: \1{{ pam_module_control }} \2
    register: result_pam_module_edit
    when:
    - result_pam_line_other_control_present.found == 1

  - name: Set Deny For Failed Password Attempts - Ensure the required PAM module line
      is included in /etc/pam.d/login
    ansible.builtin.lineinfile:
      dest: /etc/pam.d/login
      line: auth    {{ pam_module_control }}    pam_tally2.so
    register: result_pam_module_add
    when:
    - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
      > 1

  - name: Set Deny For Failed Password Attempts - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present is defined
    - result_authselect_present.stat.exists
    - |-
      (result_pam_module_add is defined and result_pam_module_add.changed)
       or (result_pam_module_edit is defined and result_pam_module_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_line_present.found is defined
  - result_pam_line_present.found == 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Define a fact for control already
    filtered in case filters are used
  ansible.builtin.set_fact:
    pam_module_control: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Check if the required PAM module option
    is present in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    regexp: ^\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s*.*\sdeny\b
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_module_accounts_passwords_pam_tally2_option_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Ensure the "deny" PAM option for "pam_tally2.so"
    is included in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    backrefs: true
    regexp: ^(\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so.*)
    line: \1 deny={{ var_password_pam_tally2 }}
    state: present
  register: result_pam_accounts_passwords_pam_tally2_add
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_accounts_passwords_pam_tally2_option_present.found == 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Ensure the required value for "deny"
    PAM option from "pam_tally2.so" in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    backrefs: true
    regexp: ^(\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s+.*)(deny)=[0-9a-zA-Z]+\s*(.*)
    line: \1\2={{ var_password_pam_tally2 }} \3
  register: result_pam_accounts_passwords_pam_tally2_edit
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_accounts_passwords_pam_tally2_option_present.found > 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Define a fact for control already
    filtered in case filters are used
  ansible.builtin.set_fact:
    pam_module_control: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Check if expected PAM module line
    is present in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    regexp: ^\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s*.*
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_line_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Include or update the PAM module line
    in /etc/pam.d/login
  block:

  - name: Set Deny For Failed Password Attempts - Check if required PAM module line
      is present in /etc/pam.d/login with different control
    ansible.builtin.lineinfile:
      path: /etc/pam.d/login
      regexp: ^\s*auth\s+.*\s+pam_tally2.so\s*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_other_control_present

  - name: Set Deny For Failed Password Attempts - Ensure the correct control for the
      required PAM module line in /etc/pam.d/login
    ansible.builtin.replace:
      dest: /etc/pam.d/login
      regexp: ^(\s*auth\s+).*(\bpam_tally2.so.*)
      replace: \1{{ pam_module_control }} \2
    register: result_pam_module_edit
    when:
    - result_pam_line_other_control_present.found == 1

  - name: Set Deny For Failed Password Attempts - Ensure the required PAM module line
      is included in /etc/pam.d/login
    ansible.builtin.lineinfile:
      dest: /etc/pam.d/login
      insertafter: (fail)
      line: auth    {{ pam_module_control }}    pam_tally2.so
    register: result_pam_module_add
    when:
    - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
      > 1

  - name: Set Deny For Failed Password Attempts - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present is defined
    - result_authselect_present.stat.exists
    - |-
      (result_pam_module_add is defined and result_pam_module_add.changed)
       or (result_pam_module_edit is defined and result_pam_module_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_line_present.found is defined
  - result_pam_line_present.found == 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Define a fact for control already
    filtered in case filters are used
  ansible.builtin.set_fact:
    pam_module_control: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Check if the required PAM module option
    is present in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    regexp: ^\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s*.*\sonerr\b
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_module_accounts_passwords_pam_tally2_option_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Ensure the "onerr" PAM option for
    "pam_tally2.so" is included in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    backrefs: true
    regexp: ^(\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so.*)
    line: \1 onerr=fail
    state: present
  register: result_pam_accounts_passwords_pam_tally2_add
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_accounts_passwords_pam_tally2_option_present.found == 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Ensure the required value for "onerr"
    PAM option from "pam_tally2.so" in /etc/pam.d/login
  ansible.builtin.lineinfile:
    path: /etc/pam.d/login
    backrefs: true
    regexp: ^(\s*auth\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s+.*)(onerr)=[0-9a-zA-Z]+\s*(.*)
    line: \1\2=fail \3
  register: result_pam_accounts_passwords_pam_tally2_edit
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_accounts_passwords_pam_tally2_option_present.found > 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Define a fact for control already
    filtered in case filters are used
  ansible.builtin.set_fact:
    pam_module_control: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Check if expected PAM module line
    is present in /etc/pam.d/common-account
  ansible.builtin.lineinfile:
    path: /etc/pam.d/common-account
    regexp: ^\s*account\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s*.*
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_line_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Include or update the PAM module line
    in /etc/pam.d/common-account
  block:

  - name: Set Deny For Failed Password Attempts - Check if required PAM module line
      is present in /etc/pam.d/common-account with different control
    ansible.builtin.lineinfile:
      path: /etc/pam.d/common-account
      regexp: ^\s*account\s+.*\s+pam_tally2.so\s*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_other_control_present

  - name: Set Deny For Failed Password Attempts - Ensure the correct control for the
      required PAM module line in /etc/pam.d/common-account
    ansible.builtin.replace:
      dest: /etc/pam.d/common-account
      regexp: ^(\s*account\s+).*(\bpam_tally2.so.*)
      replace: \1{{ pam_module_control }} \2
    register: result_pam_module_edit
    when:
    - result_pam_line_other_control_present.found == 1

  - name: Set Deny For Failed Password Attempts - Ensure the required PAM module line
      is included in /etc/pam.d/common-account
    ansible.builtin.lineinfile:
      dest: /etc/pam.d/common-account
      line: account    {{ pam_module_control }}    pam_tally2.so
    register: result_pam_module_add
    when:
    - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
      > 1

  - name: Set Deny For Failed Password Attempts - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present is defined
    - result_authselect_present.stat.exists
    - |-
      (result_pam_module_add is defined and result_pam_module_add.changed)
       or (result_pam_module_edit is defined and result_pam_module_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_line_present.found is defined
  - result_pam_line_present.found == 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Define a fact for control already
    filtered in case filters are used
  ansible.builtin.set_fact:
    pam_module_control: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Check if the required PAM module option
    is present in /etc/pam.d/common-account
  ansible.builtin.lineinfile:
    path: /etc/pam.d/common-account
    regexp: ^\s*account\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so\s*.*\s\b
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_module_accounts_passwords_pam_tally2_option_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set Deny For Failed Password Attempts - Ensure the "" PAM option for "pam_tally2.so"
    is included in /etc/pam.d/common-account
  ansible.builtin.lineinfile:
    path: /etc/pam.d/common-account
    backrefs: true
    regexp: ^(\s*account\s+{{ pam_module_control | regex_escape() }}\s+pam_tally2.so.*)
    line: \1
    state: present
  register: result_pam_accounts_passwords_pam_tally2_add
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_accounts_passwords_pam_tally2_option_present.found == 0
  tags:
  - CCE-85554-4
  - DISA-STIG-SLES-15-020010
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_tally2
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_tally2='5'

# Use a non-number regexp to force update of the value of the deny option




if ! grep -qP "^\s*auth\s+required\s+pam_tally2.so\s*.*" "/etc/pam.d/login"; then
    # Line matching group + control + module was not found. Check group + module.
    if [ "$(grep -cP '^\s*auth\s+.*\s+pam_tally2.so\s*' "/etc/pam.d/login")" -eq 1 ]; then
        # The control is updated only if one single line matches.
        sed -i -E --follow-symlinks "s/^(\s*auth\s+).*(\bpam_tally2.so.*)/\1required \2/" "/etc/pam.d/login"
    else
        echo "auth    required    pam_tally2.so" >> "/etc/pam.d/login"
    fi
fi
# Check the option
if ! grep -qP "^\s*auth\s+required\s+pam_tally2.so\s*.*\sdeny\b" "/etc/pam.d/login"; then
    sed -i -E --follow-symlinks "/\s*auth\s+required\s+pam_tally2.so.*/ s/$/ deny=${var_password_pam_tally2}/" "/etc/pam.d/login"
else
    sed -i -E --follow-symlinks "s/(\s*auth\s+required\s+pam_tally2.so\s+.*)(deny=)[[:alnum:]]+\s*(.*)/\1\2${var_password_pam_tally2} \3/" "/etc/pam.d/login"
fi
if ! grep -qP "^\s*auth\s+required\s+pam_tally2.so\s*.*" "/etc/pam.d/login"; then
    # Line matching group + control + module was not found. Check group + module.
    if [ "$(grep -cP '^\s*auth\s+.*\s+pam_tally2.so\s*' "/etc/pam.d/login")" -eq 1 ]; then
        # The control is updated only if one single line matches.
        sed -i -E --follow-symlinks "s/^(\s*auth\s+).*(\bpam_tally2.so.*)/\1required \2/" "/etc/pam.d/login"
    else
        LAST_MATCH_LINE=$(grep -nP "(fail)" "/etc/pam.d/login" | tail -n 1 | cut -d: -f 1)
        if [ ! -z $LAST_MATCH_LINE ]; then
            sed -i --follow-symlinks $LAST_MATCH_LINE" a auth     required    pam_tally2.so" "/etc/pam.d/login"
        else
            echo "auth    required    pam_tally2.so" >> "/etc/pam.d/login"
        fi
    fi
fi
# Check the option
if ! grep -qP "^\s*auth\s+required\s+pam_tally2.so\s*.*\sonerr\b" "/etc/pam.d/login"; then
    sed -i -E --follow-symlinks "/\s*auth\s+required\s+pam_tally2.so.*/ s/$/ onerr=fail/" "/etc/pam.d/login"
else
    sed -i -E --follow-symlinks "s/(\s*auth\s+required\s+pam_tally2.so\s+.*)(onerr=)[[:alnum:]]+\s*(.*)/\1\2fail \3/" "/etc/pam.d/login"
fi
if ! grep -qP "^\s*account\s+required\s+pam_tally2.so\s*.*" "/etc/pam.d/common-account"; then
    # Line matching group + control + module was not found. Check group + module.
    if [ "$(grep -cP '^\s*account\s+.*\s+pam_tally2.so\s*' "/etc/pam.d/common-account")" -eq 1 ]; then
        # The control is updated only if one single line matches.
        sed -i -E --follow-symlinks "s/^(\s*account\s+).*(\bpam_tally2.so.*)/\1required \2/" "/etc/pam.d/common-account"
    else
        echo "account    required    pam_tally2.so" >> "/etc/pam.d/common-account"
    fi
fi
# Check the option
if ! grep -qP "^\s*account\s+required\s+pam_tally2.so\s*.*\s\b" "/etc/pam.d/common-account"; then
    sed -i -E --follow-symlinks "/\s*account\s+required\s+pam_tally2.so.*/ s/$/ /" "/etc/pam.d/common-account"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Set Password Quality Requirements   Group contains 1 group and 7 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 man pages pam_pwquality(8) provide information on the capabilities and configuration of each.
Group   Set Password Quality Requirements, if using pam_cracklib   Group contains 7 rules
[ref]   The pam_cracklib PAM module can be configured to meet requirements for a variety of policies.

For example, to configure pam_cracklib to require at least one uppercase character, lowercase character, digit, and other (special) character, locate the following line in /etc/pam.d/system-auth:
password requisite pam_cracklib.so try_first_pass retry=3
and then alter it to read:
password required pam_cracklib.so try_first_pass retry=3 maxrepeat=3 minlen=14 dcredit=-1 ucredit=-1 ocredit=-1 lcredit=-1 difok=4
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth. The arguments can be modified to ensure compliance with your organization's security policy. Discussion of each parameter follows.
Warning:  Note that the password quality requirements are not enforced for the root account for some reason.

Rule   Set Password Strength Minimum Digit Characters   [ref]

The pam_cracklib 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_cracklib will grant +1 additional length credit for each digit. Add dcredit=-1 after pam_cracklib.so to require use of a digit in passwords.
Rationale:
Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_dcredit
Identifiers:

CCE-85564-3

References:
disaCCI-000194
pcidssReq-8.2.3
os-srgSRG-OS-000071-GPOS-00039
stigidSLES-15-020150
cis5.3.1
anssiR31
pcidss48.3.6
stigrefSV-234884r622137_rule

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

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "dcredit={{ var_password_pam_dcredit
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+dcredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_dcredit }}\g<2>
    backrefs: true
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "dcredit" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+dcredit(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "dcredit" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> dcredit={{ var_password_pam_dcredit }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"dcredit" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85564-3
  - DISA-STIG-SLES-15-020150
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_dcredit='-1'

VALUES+=("$var_password_pam_dcredit")
VALUE_NAMES+=("dcredit")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

Rule   Set Password Strength Minimum Different Characters   [ref]

The pam_cracklib module's difok parameter controls requirements for usage of different characters during a password change. The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different. Make sure the difok parameter for the pam_cracklib module is configured to greater than or equal to 8.
Rationale:
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_cracklib_accounts_password_pam_difok
Identifiers:

CCE-85677-3

References:
disaCCI-000195
nistIA-5(1).1(v), IA-5(1)(b)
os-srgSRG-OS-000072-GPOS-00040
stigidSLES-15-020160
stigrefSV-234885r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value var_password_pam_difok # promote to variable
  set_fact:
    var_password_pam_difok: !!str 8
  tags:
    - always

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "difok={{ var_password_pam_difok
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+difok=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_difok }}\g<2>
    backrefs: true
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "difok" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+difok(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "difok" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> difok={{ var_password_pam_difok }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"difok" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85677-3
  - DISA-STIG-SLES-15-020160
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(1).1(v)
  - cracklib_accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_difok='8'

VALUES+=("$var_password_pam_difok")
VALUE_NAMES+=("difok")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

Rule   Set Password Strength Minimum Lowercase Characters   [ref]

The pam_cracklib 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_cracklib will grant +1 additional length credit for each lowercase character. Add lcredit=-1 after pam_cracklib.so to require use of a lowercase character in passwords.
Rationale:
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_cracklib_accounts_password_pam_lcredit
Identifiers:

CCE-85676-5

References:
disaCCI-000193
nistIA-5(1)(a), IA-5(1).1(v)
pcidssReq-8.2.3
os-srgSRG-OS-000070-GPOS-00038
stigidSLES-15-020140
cis5.3.1
anssiR31
pcidss48.3.6
stigrefSV-234883r622137_rule

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

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "lcredit={{ var_password_pam_lcredit
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+lcredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_lcredit }}\g<2>
    backrefs: true
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "lcredit" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+lcredit(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "lcredit" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> lcredit={{ var_password_pam_lcredit }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"lcredit" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85676-5
  - DISA-STIG-SLES-15-020140
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_lcredit='-1'

VALUES+=("$var_password_pam_lcredit")
VALUE_NAMES+=("lcredit")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

Rule   Set Password Minimum Length   [ref]

The pam_cracklib module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=15 to set minimum password length requirements.
Rationale:
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 compromise the password.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_minlen
Identifiers:

CCE-85573-4

References:
disaCCI-000205
pcidssReq-8.2.3
os-srgSRG-OS-000078-GPOS-00046
stigidSLES-15-020260
cis5.3.1
anssiR31
pcidss48.3.6
stigrefSV-234895r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value var_password_pam_minlen # promote to variable
  set_fact:
    var_password_pam_minlen: !!str 15
  tags:
    - always

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "minlen={{ var_password_pam_minlen
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+minlen=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_minlen }}\g<2>
    backrefs: true
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "minlen" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+minlen(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "minlen" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> minlen={{ var_password_pam_minlen }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"minlen" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85573-4
  - DISA-STIG-SLES-15-020260
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - cracklib_accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_minlen='15'

VALUES+=("$var_password_pam_minlen")
VALUE_NAMES+=("minlen")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

Rule   Set Password Strength Minimum Special Characters   [ref]

The pam_cracklib 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_cracklib will grant +1 additional length credit for each special character. Make sure the ocredit parameter for the pam_cracklib module is set to less than or equal to -1. For example, ocredit=-1 .
Rationale:
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_cracklib_accounts_password_pam_ocredit
Identifiers:

CCE-85574-2

References:
disaCCI-001619
nistIA-5(a), IA-5(v)
pcidssReq-8.2.3
os-srgSRG-OS-000266-GPOS-00101
stigidSLES-15-020270
cis5.3.1
anssiR31
stigrefSV-234896r622137_rule

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

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "ocredit={{ var_password_pam_ocredit
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+ocredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_ocredit }}\g<2>
    backrefs: true
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "ocredit" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+ocredit(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "ocredit" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> ocredit={{ var_password_pam_ocredit }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"ocredit" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85574-2
  - DISA-STIG-SLES-15-020270
  - NIST-800-53-IA-5(a)
  - NIST-800-53-IA-5(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ocredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_ocredit='-1'

VALUES+=("$var_password_pam_ocredit")
VALUE_NAMES+=("ocredit")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

Rule   Set Password Retry Limit   [ref]

The pam_cracklib module's retry parameter controls the maximum number of times to prompt the user for the password before returning with error. Make sure it is configured with a value that is no more than 3. For example, retry=1.
Rationale:
To reduce opportunities for successful guesses and brute-force attacks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_retry
Identifiers:

CCE-85575-9

References:
disaCCI-000366
pcidssReq-8.1.6, Req-8.1.7
os-srgSRG-OS-000480-GPOS-00225
stigidSLES-15-020290
cis5.3.1
pcidss48.3.4
stigrefSV-234897r622137_rule

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

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "retry={{ var_password_pam_retry
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+retry=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_retry }}\g<2>
    backrefs: true
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "retry" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+retry(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "retry" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> retry={{ var_password_pam_retry }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"retry" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85575-9
  - DISA-STIG-SLES-15-020290
  - PCI-DSS-Req-8.1.6
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - cracklib_accounts_password_pam_retry
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_retry='3'

VALUES+=("$var_password_pam_retry")
VALUE_NAMES+=("retry")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done

Rule   Set Password Strength Minimum Uppercase Characters   [ref]

The pam_cracklib 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_cracklib will grant +1 additional length credit for each uppercase character. Add ucredit=-1 after pam_cracklib.so to require use of an upper case character in passwords.
Rationale:
Requiring a minimum number of uppercase characters makes password guessing attacks more difficult by ensuring a larger search space.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_ucredit
Identifiers:

CCE-85675-7

References:
disaCCI-000192
nistIA-5(1)(a), IA-5(1).1(v)
pcidssReq-8.2.3
os-srgSRG-OS-000069-GPOS-00037
stigidSLES-15-020130
cis5.3.1
anssiR31
stigrefSV-234882r622137_rule

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

- name: Set control_flag fact
  set_fact:
    control_flag: requisite
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
  register: check_pam_module_result
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
  lineinfile:
    path: /etc/pam.d/common-password
    line: password requisite pam_cracklib.so
    state: present
  when: check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure 'pam_cracklib.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
    line: \g<1>requisite\g<2>
    backrefs: true
  when: control_flag|length
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure "pam_cracklib.so" module has argument "ucredit={{ var_password_pam_ucredit
    }}"
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+ucredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
    line: \g<1>{{ var_password_pam_ucredit }}\g<2>
    backrefs: true
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the presence of "ucredit" argument in "pam_cracklib.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+ucredit(=|\s|\s*$)' /etc/pam.d/common-password || true
  register: check_pam_module_argument_result
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add "ucredit" argument to "pam_cracklib.so" module
  lineinfile:
    path: /etc/pam.d/common-password
    regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> ucredit={{ var_password_pam_ucredit }}\g<2>
    backrefs: true
  when: check_pam_module_argument_result is not skipped and '"ucredit" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85675-7
  - DISA-STIG-SLES-15-020130
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSS-Req-8.2.3
  - cracklib_accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()

var_password_pam_ucredit='-1'

VALUES+=("$var_password_pam_ucredit")
VALUE_NAMES+=("ucredit")
ARGS+=("")
NEW_ARGS+=("")

for idx in "${!VALUES[@]}"
do
    if [ -e "/etc/pam.d/common-password" ] ; then
        valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
        # non-empty values need to be preceded by an equals sign
        [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
        # add an equals sign to non-empty values
        [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

        # fix the value for 'option' if one exists but does not match 'valueRegex'
        if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"

        # add 'option=default' if option is not set
        elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
                grep    -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then

            sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
        # add a new entry if none exists
        elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
            echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
        fi
    else
        echo "/etc/pam.d/common-password doesn't exist" >&2
    fi
done

for idx in "${!ARGS[@]}"
do
    if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
        sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
    fi
done
Group   Set Password Hashing Algorithm   Group contains 2 rules
[ref]   The system's default algorithm for storing password hashes in /etc/shadow is SHA-512. This can be configured in several locations.

Rule   Set PAM's Common Authentication Hashing Algorithm   [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In /etc/pam.d/common-auth, the auth section of the file controls which PAM modules execute during a password change. Set the pam_unix.so module in the auth section to include the argument sha512, as shown below:
auth   required    pam_unix.so sha512 other arguments...
         

This will help ensure when local users change their authentication method, hashes for the new authentications will be generated using the SHA-512 algorithm. This is the default.
Rationale:
Unapproved mechanisms used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and data may be compromised. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the crypt_style configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_commonauth
Identifiers:

CCE-85754-0

References:
disaCCI-000803
nistIA-7, IA-7.1
pcidssReq-8.2.1
os-srgSRG-OS-000120-GPOS-00061
pcidss48.3.2

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Set control_flag fact
  set_fact:
    control_flag: required
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Check to see if 'pam_unix.so' module is configured in '/etc/pam.d/common-auth'
  shell: |
    set -o pipefail
    grep -E '^\s*auth\s+\S+\s+pam_unix.so' /etc/pam.d/common-auth || true
  register: check_pam_module_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Configure 'pam_unix.so' module in '/etc/pam.d/common-auth'
  lineinfile:
    path: /etc/pam.d/common-auth
    line: auth required pam_unix.so
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_result.stdout is defined and '"pam_unix.so" not in check_pam_module_result.stdout'
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Ensure 'pam_unix.so' module has conforming control flag
  lineinfile:
    path: /etc/pam.d/common-auth
    regexp: ^(\s*auth\s+)\S+(\s+pam_unix.so\s+.*)
    line: \g<1>required\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - control_flag|length
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Set argument_value fact
  set_fact:
    argument_value: ''
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Ensure "pam_unix.so" module has argument "sha512"
  lineinfile:
    path: /etc/pam.d/common-auth
    regexp: ^(\s*auth\s+required\s+pam_unix.so(?:\s+\S+)*\s+sha512=)(?!)\S*((\s+\S+)*\s*\\*\s*)$
    line: \g<1>\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - argument_value|length
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Check the presence of "sha512" argument in "pam_unix.so" module
  shell: |
    set -o pipefail
    grep -E '^\s*auth\s+required\s+pam_unix.so.*\s+sha512(=|\s|\s*$)' /etc/pam.d/common-auth || true
  register: check_pam_module_argument_result
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

- name: Add "sha512" argument to "pam_unix.so" module
  lineinfile:
    path: /etc/pam.d/common-auth
    regexp: ^(\s*auth\s+required\s+pam_unix.so)((\s+\S+)*\s*(\\)*$)
    line: \g<1> sha512\g<2>
    backrefs: true
  when:
  - '"pam" in ansible_facts.packages'
  - check_pam_module_argument_result is not skipped and '"sha512" not in check_pam_module_argument_result.stdout'
  tags:
  - CCE-85754-0
  - NIST-800-53-IA-7
  - NIST-800-53-IA-7.1
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_commonauth

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

if [ -e "/etc/pam.d/common-auth" ] ; then
    valueRegex="" defaultValue=""
    # non-empty values need to be preceded by an equals sign
    [ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
    # add an equals sign to non-empty values
    [ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"

    # fix 'type' if it's wrong
    if grep -q -P "^\\s*(?"'!'"auth\\s)[[:alnum:]]+\\s+[[:alnum:]]+\\s+pam_unix.so" < "/etc/pam.d/common-auth" ; then
        sed --follow-symlinks -i -E -e "s/^(\\s*)[[:alnum:]]+(\\s+[[:alnum:]]+\\s+pam_unix.so)/\\1auth\\2/" "/etc/pam.d/common-auth"
    fi

    # fix 'control' if it's wrong
    if grep -q -P "^\\s*auth\\s+(?"'!'"required)[[:alnum:]]+\\s+pam_unix.so" < "/etc/pam.d/common-auth" ; then
        sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+)[[:alnum:]]+(\\s+pam_unix.so)/\\1required\\2/" "/etc/pam.d/common-auth"
    fi

    # fix the value for 'option' if one exists but does not match 'valueRegex'
    if grep -q -P "^\\s*auth\\s+required\\s+pam_unix.so(\\s.+)?\\s+sha512(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-auth" ; then
        sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+required\\s+pam_unix.so(\\s.+)?\\s)sha512=[^[:space:]]*/\\1sha512${defaultValue}/" "/etc/pam.d/common-auth"

    # add 'option=default' if option is not set
    elif grep -q -E "^\\s*auth\\s+required\\s+pam_unix.so" < "/etc/pam.d/common-auth" &&
            grep    -E "^\\s*auth\\s+required\\s+pam_unix.so" < "/etc/pam.d/common-auth" | grep -q -E -v "\\ssha512(=|\\s|\$)" ; then

        sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+required\\s+pam_unix.so[^\\n]*)/\\1 sha512${defaultValue}/" "/etc/pam.d/common-auth"
    # add a new entry if none exists
    elif ! grep -q -P "^\\s*auth\\s+required\\s+pam_unix.so(\\s.+)?\\s+sha512${valueRegex}(\\s|\$)" < "/etc/pam.d/common-auth" ; then
        echo "auth required pam_unix.so sha512${defaultValue}" >> "/etc/pam.d/common-auth"
    fi
else
    echo "/etc/pam.d/common-auth doesn't exist" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set PAM''s Password Hashing Algorithm   [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In "/etc/pam.d/common-password", the password section of the file controls which PAM modules execute during a password change. Set the pam_unix.so module in the password section to include the argument sha512, as shown below:
password    required    pam_unix.so sha512 other arguments...
         

This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default.
Rationale:
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text.

This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the crypt_style configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_systemauth
Identifiers:

CCE-85565-0

References:
cis-csc1, 12, 15, 16, 5
cjis5.6.2.2
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.13.11
disaCCI-000196, CCI-000803
isa-62443-20094.3.3.2.2, 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
isa-62443-2013SR 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
ism0418, 1055, 1402
iso27001-2013A.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
nistIA-5(c), IA-5(1)(c), CM-6(a)
nist-csfPR.AC-1, PR.AC-6, PR.AC-7
pcidssReq-8.2.1
os-srgSRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061
stigidSLES-15-020170
anssiR68
pcidss48.3.2
stigrefSV-234886r877397_rule

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85565-0
  - CJIS-5.6.2.2
  - DISA-STIG-SLES-15-020170
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

- name: Set PAM's Password Hashing Algorithm - Check if /etc/pam.d/common-password
    file is present
  ansible.builtin.stat:
    path: /etc/pam.d/common-password
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85565-0
  - CJIS-5.6.2.2
  - DISA-STIG-SLES-15-020170
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

- name: Set PAM's Password Hashing Algorithm - Check the proper remediation for the
    system
  block:

  - name: Set PAM's Password Hashing Algorithm - Define the PAM file to be edited
      as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/common-password

  - name: Set PAM's Password Hashing Algorithm - Check if system relies on authselect
      tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Set PAM's Password Hashing Algorithm - Ensure authselect custom profile
      is used if authselect is present
    block:

    - name: Set PAM's Password Hashing Algorithm - Check integrity of authselect current
        profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

    - name: Set PAM's Password Hashing Algorithm - Informative message based on the
        authselect integrity check result
      ansible.builtin.assert:
        that:
        - result_authselect_check_cmd.rc == 0
        fail_msg:
        - authselect integrity check failed. Remediation aborted!
        - This remediation could not be applied because an authselect profile was
          not selected or the selected profile is not intact.
        - It is not recommended to manually edit the PAM files when authselect tool
          is available.
        - In cases where the default authselect profile does not cover a specific
          demand, a custom authselect profile is recommended.
        success_msg:
        - authselect integrity check passed

    - name: Set PAM's Password Hashing Algorithm - Get authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Set PAM's Password Hashing Algorithm - Define the current authselect profile
        as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Define the new authselect custom
        profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Get authselect current features
        to also enable them in the custom profile
      ansible.builtin.shell:
        cmd: authselect current | tail -n+3 | awk '{ print $2 }'
      register: result_authselect_features
      changed_when: false
      when:
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Check if any custom profile with
        the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
        based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Set PAM's Password Hashing Algorithm - Ensure the authselect custom profile
        is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Set PAM's Password Hashing Algorithm - Restore the authselect features
        in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Set PAM's Password Hashing Algorithm - Change the PAM file to be edited
        according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Set PAM's Password Hashing Algorithm - Define a fact for control already
      filtered in case filters are used
    ansible.builtin.set_fact:
      pam_module_control: required

  - name: Set PAM's Password Hashing Algorithm - Check if expected PAM module line
      is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

  - name: Set PAM's Password Hashing Algorithm - Include or update the PAM module
      line in {{ pam_file_path }}
    block:

    - name: Set PAM's Password Hashing Algorithm - Check if required PAM module line
        is present in {{ pam_file_path }} with different control
      ansible.builtin.lineinfile:
        path: '{{ pam_file_path }}'
        regexp: ^\s*password\s+.*\s+pam_unix.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: Set PAM's Password Hashing Algorithm - Ensure the correct control for
        the required PAM module line in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
        replace: \1{{ pam_module_control }} \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: Set PAM's Password Hashing Algorithm - Ensure the required PAM module
        line is included in {{ pam_file_path }}
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        line: password    {{ pam_module_control }}    pam_unix.so
      register: result_pam_module_add
      when:
      - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
        > 1

    - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present is defined
      - result_authselect_present.stat.exists
      - |-
        (result_pam_module_add is defined and result_pam_module_add.changed)
         or (result_pam_module_edit is defined and result_pam_module_edit.changed)
    when:
    - result_pam_line_present.found is defined
    - result_pam_line_present.found == 0

  - name: Set PAM's Password Hashing Algorithm - Define a fact for control already
      filtered in case filters are used
    ansible.builtin.set_fact:
      pam_module_control: required

  - name: Set PAM's Password Hashing Algorithm - Check if the required PAM module
      option is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*\ssha512\b
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_module_set_password_hashing_algorithm_systemauth_option_present

  - name: Set PAM's Password Hashing Algorithm - Ensure the "sha512" PAM option for
      "pam_unix.so" is included in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so.*)
      line: \1 sha512
      state: present
    register: result_pam_set_password_hashing_algorithm_systemauth_add
    when:
    - result_pam_module_set_password_hashing_algorithm_systemauth_option_present.found
      == 0

  - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam_set_password_hashing_algorithm_systemauth_add is defined and result_pam_set_password_hashing_algorithm_systemauth_add.changed)
       or (result_pam_set_password_hashing_algorithm_systemauth_edit is defined and result_pam_set_password_hashing_algorithm_systemauth_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - CCE-85565-0
  - CJIS-5.6.2.2
  - DISA-STIG-SLES-15-020170
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

if [ -e "/etc/pam.d/common-password" ] ; then
    PAM_FILE_PATH="/etc/pam.d/common-password"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

        CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
        # If not already in use, a custom profile is created preserving the enabled features.
        if [[ ! $CURRENT_PROFILE == custom/* ]]; then
            ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
            authselect create-profile hardening -b $CURRENT_PROFILE
            CURRENT_PROFILE="custom/hardening"
            
            authselect apply-changes -b --backup=before-hardening-custom-profile
            authselect select $CURRENT_PROFILE
            for feature in $ENABLED_FEATURES; do
                authselect enable-feature $feature;
            done
            
            authselect apply-changes -b --backup=after-hardening-custom-profile
        fi
        PAM_FILE_NAME=$(basename "/etc/pam.d/common-password")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP "^\s*password\s+required\s+pam_unix.so\s*.*" "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_unix.so.*)/\1required \2/" "$PAM_FILE_PATH"
            else
                echo "password    required    pam_unix.so" >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP "^\s*password\s+required\s+pam_unix.so\s*.*\ssha512\b" "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks "/\s*password\s+required\s+pam_unix.so.*/ s/$/ sha512/" "$PAM_FILE_PATH"
        fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/common-password was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Protect Physical Console Access   Group contains 2 groups and 3 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 2 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   Hardware Tokens for Authentication   Group contains 2 rules

Rule   Configure Smart Card Certificate Authority Validation   [ref]

Configure the operating system to do certificate status checking for PKI authentication. Modify all of the cert_policy lines in /etc/pam_pkcs11/pam_pkcs11.conf to include ca like so:
cert_policy = ca, ocsp_on, signature;
Rationale:
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device.

Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DoD Common Access Card.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_smartcard_configure_ca
Identifiers:

CCE-83272-5

References:
disaCCI-000185, CCI-001991
os-srgSRG-OS-000066-GPOS-00034, SRG-OS-000384-GPOS-00167
stigidSLES-15-010170
stigrefSV-234817r854185_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Package facts
  package_facts: null
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ''
  tags:
  - CCE-83272-5
  - DISA-STIG-SLES-15-010170
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - smartcard_configure_ca

- name: Replace 'none' from cert_policy
  replace:
    path: /etc/pam_pkcs11/pam_pkcs11.conf
    regexp: (^\s*cert_policy\s*=\s*)none\s*;(\s*$)
    replace: \g<1>ocsp_on,ca,signature;\g<2>
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '''pam_pkcs11'' in ansible_facts.packages'
  tags:
  - CCE-83272-5
  - DISA-STIG-SLES-15-010170
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - smartcard_configure_ca

- name: Add 'ca' parameter for cert_policy in /etc/pam_pkcs11/pam_pkcs11.conf
  replace:
    path: /etc/pam_pkcs11/pam_pkcs11.conf
    regexp: (^\s*cert_policy\s*=\s*)(?!.*ca)(.*)
    replace: \g<1>ca,\g<2>
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '''pam_pkcs11'' in ansible_facts.packages'
  tags:
  - CCE-83272-5
  - DISA-STIG-SLES-15-010170
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - smartcard_configure_ca

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if rpm -qa pam_pkcs11; then
    if grep "^\s*cert_policy" /etc/pam_pkcs11/pam_pkcs11.conf | grep -q "ca"; then
        sed -i "/^\s*#/! s/cert_policy.*/cert_policy = ca, ocsp_on, signature;/g" /etc/pam_pkcs11/pam_pkcs11.conf
    fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure Smart Card Certificate Status Checking   [ref]

Configure the operating system to do certificate status checking for PKI authentication. Modify all of the cert_policy lines in /etc/pam_pkcs11/pam_pkcs11.conf to include ocsp_on like so:
cert_policy = ca, ocsp_on, signature;
Rationale:
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device.

Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DoD Common Access Card.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_smartcard_configure_cert_checking
Identifiers:

CCE-83293-1

References:
disaCCI-001948, CCI-001953, CCI-001954
os-srgSRG-OS-000375-GPOS-00160, SRG-OS-000376-GPOS-00161, SRG-OS-000377-GPOS-00162, SRG-OS-000384-GPOS-00167
stigidSLES-15-010470
stigrefSV-234855r854201_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Package facts
  package_facts: null
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture != "s390x"
  tags:
  - CCE-83293-1
  - DISA-STIG-SLES-15-010470
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - smartcard_configure_cert_checking

- name: Replace 'none' from cert_policy
  replace:
    path: /etc/pam_pkcs11/pam_pkcs11.conf
    regexp: (^\s*cert_policy\s*=\s*)none\s*;(\s*$)
    replace: \g<1>ocsp_on,ca,signature;\g<2>
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture != "s390x"
  - '''pam_pkcs11'' in ansible_facts.packages'
  tags:
  - CCE-83293-1
  - DISA-STIG-SLES-15-010470
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - smartcard_configure_cert_checking

- name: Add 'ocsp_on' parameter for cert_policy in /etc/pam_pkcs11/pam_pkcs11.conf
  replace:
    path: /etc/pam_pkcs11/pam_pkcs11.conf
    regexp: (^\s*cert_policy\s*=\s*)(?!.*ocsp_on)(.*)
    replace: \g<1>ocsp_on,\g<2>
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture != "s390x"
  - '''pam_pkcs11'' in ansible_facts.packages'
  tags:
  - CCE-83293-1
  - DISA-STIG-SLES-15-010470
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - smartcard_configure_cert_checking

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { ! grep -q s390x /proc/sys/kernel/osrelease; }; then

zypper install -y "pam_pkcs11"

if grep "^\s*cert_policy" /etc/pam_pkcs11/pam_pkcs11.conf | grep -qv "ocsp_on"; then
	sed -i "/^\s*#/! s/cert_policy.*/cert_policy = ca, ocsp_on, signature;/g" /etc/pam_pkcs11/pam_pkcs11.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

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:

CCE-85665-8

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
cui3.4.5
disaCCI-000366
hipaa164.308(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)
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nistCM-6(b), CM-6.1(iv)
nist-csfPR.AC-4, PR.DS-5
osppFAU_GEN.1.2
os-srgSRG-OS-000324-GPOS-00125, SRG-OS-000480-GPOS-00227
stigidSLES-15-040062
stigrefSV-234990r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:disable
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85665-8
  - DISA-STIG-SLES-15-040062
  - NIST-800-171-3.4.5
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - disable_ctrlaltdel_burstaction
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed

- name: Disable Ctrl-Alt-Del Burst Action
  lineinfile:
    dest: /etc/systemd/system.conf
    state: present
    regexp: ^CtrlAltDelBurstAction
    line: CtrlAltDelBurstAction=none
    create: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"systemd" in ansible_facts.packages'
  tags:
  - CCE-85665-8
  - DISA-STIG-SLES-15-040062
  - NIST-800-171-3.4.5
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - disable_ctrlaltdel_burstaction
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q systemd; }; then

# 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' <<< "^CtrlAltDelBurstAction=")

# shellcheck disable=SC2059
printf -v formatted_output "%s=%s" "$stripped_key" "none"

# 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 -i -e "^CtrlAltDelBurstAction=\\>" "/etc/systemd/system.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^CtrlAltDelBurstAction=\\>.*/$escaped_formatted_output/gi" "/etc/systemd/system.conf"
else
    if [[ -s "/etc/systemd/system.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/systemd/system.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/systemd/system.conf"
    fi
    cce="CCE-85665-8"
    printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/systemd/system.conf" >> "/etc/systemd/system.conf"
    printf '%s\n' "$formatted_output" >> "/etc/systemd/system.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Protect Accounts by Restricting Password-Based Login   Group contains 3 groups and 6 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   Set Account Expiration Parameters   Group contains 1 rule
Group   Set Password Expiration Parameters   Group contains 4 rules
[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

Rule   Set Existing Passwords Maximum Age   [ref]

Configure non-compliant accounts to enforce a 60-day maximum password lifetime restriction by running the following command:
$ sudo chage -M 60
          USER
         
Rationale:
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_set_max_life_existing
Identifiers:

CCE-85571-8

References:
disaCCI-000199
nistIA-5(f), IA-5(1)(d), CM-6(a)
os-srgSRG-OS-000076-GPOS-00044
stigidSLES-15-020230
cis5.4.1.2
pcidss48.3.9
stigrefSV-234892r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value var_accounts_maximum_age_login_defs # promote to variable
  set_fact:
    var_accounts_maximum_age_login_defs: !!str 60
  tags:
    - always

- name: Collect users with not correct maximum time period between password changes
  ansible.builtin.command:
    cmd: awk -F':' '(/^[^:]+:[^!*]/ && ($5 > {{ var_accounts_maximum_age_login_defs
      }} || $5 == "")) {print $1}' /etc/shadow
  register: user_names
  tags:
  - CCE-85571-8
  - DISA-STIG-SLES-15-020230
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(d)
  - NIST-800-53-IA-5(f)
  - PCI-DSSv4-8.3.9
  - accounts_password_set_max_life_existing
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Change the maximum time period between password changes
  ansible.builtin.command:
    cmd: passwd -q -x {{ var_accounts_maximum_age_login_defs }} {{ item }}
  with_items: '{{ user_names.stdout_lines }}'
  when: user_names.stdout_lines | length > 0
  tags:
  - CCE-85571-8
  - DISA-STIG-SLES-15-020230
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(d)
  - NIST-800-53-IA-5(f)
  - PCI-DSSv4-8.3.9
  - accounts_password_set_max_life_existing
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

var_accounts_maximum_age_login_defs='60'


while IFS= read -r i; do
    
    passwd -q -x $var_accounts_maximum_age_login_defs $i

done <   <(awk -v var="$var_accounts_maximum_age_login_defs" -F: '(/^[^:]+:[^!*]/ && ($5 > var || $5 == "")) {print $1}' /etc/shadow)

Rule   Set Existing Passwords Minimum Age   [ref]

Configure non-compliant accounts to enforce a 24 hours/1 day minimum password lifetime by running the following command:
$ sudo chage -m 1 USER
         
Rationale:
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_set_min_life_existing
Identifiers:

CCE-85710-2

References:
disaCCI-000198
nistIA-5(1).1(v)
os-srgSRG-OS-000075-GPOS-00043
stigidSLES-15-020210
cis5.4.1.3
stigrefSV-234890r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value var_accounts_minimum_age_login_defs # promote to variable
  set_fact:
    var_accounts_minimum_age_login_defs: !!str 7
  tags:
    - always

- name: Collect users with not correct minimum time period between password changes
  command: |
    awk -F':' '(/^[^:]+:[^!*]/ && ($4 < {{ var_accounts_minimum_age_login_defs }} || $4 == "")) {print $1}' /etc/shadow
  register: user_names
  tags:
  - CCE-85710-2
  - DISA-STIG-SLES-15-020210
  - NIST-800-53-IA-5(1).1(v)
  - accounts_password_set_min_life_existing
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Change the minimum time period between password changes
  command: |
    passwd -q -n {{ var_accounts_minimum_age_login_defs }} {{ item }}
  with_items: '{{ user_names.stdout_lines }}'
  when: user_names.stdout_lines | length > 0
  tags:
  - CCE-85710-2
  - DISA-STIG-SLES-15-020210
  - NIST-800-53-IA-5(1).1(v)
  - accounts_password_set_min_life_existing
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

var_accounts_minimum_age_login_defs='7'


while IFS= read -r i; do
    
    passwd -q -n $var_accounts_minimum_age_login_defs $i

done <   <(awk -v var="$var_accounts_minimum_age_login_defs" -F: '(/^[^:]+:[^!*]/ && ($4 < var || $4 == "")) {print $1}' /etc/shadow)
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.

Rule   Direct root Logins Not Allowed   [ref]

To further limit access to the root account, administrators can disable root logins at the console by editing the /etc/securetty file. This file lists all devices the root user is allowed to login to. If the file does not exist at all, the root user can login through any communication device on the system, whether via the console or via a raw network interface. This is dangerous as user can login to the system as root via Telnet, which sends the password in plain text over the network. By default, SUSE Linux Enterprise 15's /etc/securetty file only allows the root user to login at the console physically attached to the system. To prevent root from logging in, remove the contents of this file. To prevent direct root logins, remove the contents of this file by typing the following command:
$ sudo echo > /etc/securetty
Warning:  This rule only checks the /etc/securetty file existence and its content. If you need to restrict user access using the /etc/securetty file, make sure the pam_securetty.so PAM module is properly enabled in relevant PAM files.
Rationale:
Disabling direct root logins ensures proper accountability and multifactor authentication to privileged accounts. Users will first login, then escalate to privileged (root) access via su / sudo. This is required for FISMA Low and FISMA Moderate systems.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_direct_root_logins
Identifiers:

CCE-91427-5

References:
cis-csc1, 12, 15, 16, 5
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.1.1, 3.1.6
hipaa164.308(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)
isa-62443-20094.3.3.2.2, 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
isa-62443-2013SR 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
iso27001-2013A.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
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nistIA-2, CM-6(a)
nist-csfPR.AC-1, PR.AC-6, PR.AC-7
cis5.5
anssiR33
pcidss48.6.1

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Direct root Logins Not Allowed
  copy:
    dest: /etc/securetty
    content: ''
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91427-5
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-2
  - PCI-DSSv4-8.6.1
  - low_complexity
  - low_disruption
  - medium_severity
  - no_direct_root_logins
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

echo > /etc/securetty

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Secure Session Configuration Files for Login Accounts   Group contains 1 group and 5 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 2 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
         
Note that /etc/profile also reads scrips within /etc/profile.d directory. These scripts are also valid files to set umask value. Therefore, they should also be considered during the check and properly remediated, if necessary.
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: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_umask_etc_profile
Identifiers:

CCE-91216-2

References:
cis-csc18
cobit5APO13.01, BAI03.01, BAI03.02, BAI03.03
disaCCI-000366
isa-62443-20094.3.4.3.3
iso27001-2013A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nistAC-6(1), CM-6(a)
nist-csfPR.IP-2
os-srgSRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227
cis5.4.5
anssiR36

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

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Locate Profile
    Configuration Files Where umask Is Defined
  ansible.builtin.find:
    paths:
    - /etc/profile.d
    patterns:
    - sh.local
    - '*.sh'
    contains: ^[\s]*umask\s+\d+
  register: result_profile_d_files
  tags:
  - CCE-91216-2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Replace Existing
    umask Value in Files From /etc/profile.d
  ansible.builtin.replace:
    path: '{{ item.path }}'
    regexp: ^(\s*)umask\s+\d+
    replace: \1umask {{ var_accounts_user_umask }}
  loop: '{{ result_profile_d_files.files }}'
  register: result_umask_replaced_profile_d
  when: result_profile_d_files.matched
  tags:
  - CCE-91216-2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Is
    Set in /etc/profile if Not Already Set Elsewhere
  ansible.builtin.lineinfile:
    create: true
    mode: 420
    path: /etc/profile
    line: umask {{ var_accounts_user_umask }}
  when: not result_profile_d_files.matched
  tags:
  - CCE-91216-2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Value
    For All Existing umask Definition in /etc/profile
  ansible.builtin.replace:
    path: /etc/profile
    regexp: ^(\s*)umask\s+\d+
    replace: \1umask {{ var_accounts_user_umask }}
  register: result_umask_replaced_profile
  tags:
  - CCE-91216-2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

var_accounts_user_umask='027'


readarray -t profile_files < <(find /etc/profile.d/ -type f -name '*.sh' -or -name 'sh.local')

for file in "${profile_files[@]}" /etc/profile; do
  grep -qE '^[^#]*umask' "$file" && sed -i -E "s/^(\s*umask\s*)[0-7]+/\1$var_accounts_user_umask/g" "$file"
done

if ! grep -qrE '^[^#]*umask' /etc/profile*; then
  echo "umask $var_accounts_user_umask" >> /etc/profile
fi

Rule   Set Interactive Session Timeout   [ref]

Setting the TMOUT option in /etc/profile ensures that all user sessions will terminate based on inactivity. The value of TMOUT should be exported and read only. The TMOUT setting in /etc/profile.d/autologout.sh should read as follows:
TMOUT=900
        
readonly TMOUT export TMOUT
Rationale:
Terminating an idle 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 left unattended.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_tmout
Identifiers:

CCE-83269-1

References:
cis-csc1, 12, 15, 16
cobit5DSS05.04, DSS05.10, DSS06.10
cui3.1.11
disaCCI-000057, CCI-001133, CCI-002361
isa-62443-20094.3.3.6.1, 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
isa-62443-2013SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nerc-cipCIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nistAC-12, SC-10, AC-2(5), CM-6(a)
nist-csfPR.AC-7
osppFMT_MOF_EXT.1
os-srgSRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010
stigidSLES-15-010130
cis5.4.4
anssiR32
pcidss48.6.1
stigrefSV-234813r622137_rule

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

- name: Set Interactive Session Timeout
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*TMOUT=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/profile.d/autologout.sh
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*TMOUT=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/profile.d/autologout.sh
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*TMOUT=
      line: TMOUT={{ var_accounts_tmout }}
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83269-1
  - DISA-STIG-SLES-15-010130
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Interactive Session Timeout
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*readonly\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/profile.d/autologout.sh
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*readonly\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/profile.d/autologout.sh
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*readonly\s+
      line: readonly TMOUT
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83269-1
  - DISA-STIG-SLES-15-010130
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Interactive Session Timeout
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*export\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/profile.d/autologout.sh
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*export\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/profile.d/autologout.sh
    lineinfile:
      path: /etc/profile.d/autologout.sh
      create: true
      regexp: ^\s*export\s+
      line: export TMOUT
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83269-1
  - DISA-STIG-SLES-15-010130
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set the permission for /etc/profile.d/autologout.sh
  file:
    path: /etc/profile.d/autologout.sh
    mode: '0755'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - lookup('ansible.builtin.file', '/etc/profile.d/autologout.sh', errors='warn')
  tags:
  - CCE-83269-1
  - DISA-STIG-SLES-15-010130
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_accounts_tmout='900'


if [ -f /etc/profile.d/autologout.sh ]; then
    if grep --silent '^\s*TMOUT' /etc/profile.d/autologout.sh ; then
        sed -i -E "s/^(\s*)TMOUT\s*=\s*(\w|\$)*(.*)$/\1TMOUT=$var_accounts_tmout\3/g" /etc/profile.d/autologout.sh
    fi
else
    echo -e "\n# Set TMOUT to $var_accounts_tmout per security requirements" >> /etc/profile.d/autologout.sh
    echo "TMOUT=$var_accounts_tmout" >> /etc/profile.d/autologout.sh
fi
if ! grep --silent '^\s*readonly TMOUT' /etc/profile.d/autologout.sh ; then
    echo "readonly TMOUT" >> /etc/profile.d/autologout.sh
fi

if ! grep --silent '^\s*export TMOUT' /etc/profile.d/autologout.sh ; then
    echo "export TMOUT" >> /etc/profile.d/autologout.sh
fi
chmod +x /etc/profile.d/autologout.sh

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   All Interactive User Home Directories Must Have mode 0750 Or Less Permissive   [ref]

Change the mode of interactive users home directories to 0750. To change the mode of interactive users home directory, use the following command:
$ sudo chmod 0750 /home/USER
        
Rationale:
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_home_directories
Identifiers:

CCE-85629-4

References:
disaCCI-000366
os-srgSRG-OS-000480-GPOS-00227
stigidSLES-15-040090
cis6.2.6
stigrefSV-234993r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Get all local users from /etc/passwd
  ansible.builtin.getent:
    database: passwd
    split: ':'
  tags:
  - CCE-85629-4
  - DISA-STIG-SLES-15-040090
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create local_users variable from the getent output
  ansible.builtin.set_fact:
    local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
  tags:
  - CCE-85629-4
  - DISA-STIG-SLES-15-040090
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Test for existence home directories to avoid creating them.
  ansible.builtin.stat:
    path: '{{ item.value[4] }}'
  register: path_exists
  loop: '{{ local_users }}'
  when:
  - item.value[1]|int >= 1000
  - item.value[1]|int != 65534
  tags:
  - CCE-85629-4
  - DISA-STIG-SLES-15-040090
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure interactive local users have proper permissions on their respective
    home directories
  ansible.builtin.file:
    path: '{{ item.0.value[4] }}'
    mode: u-s,g-w-s,o=-
    follow: false
    recurse: false
  loop: '{{ local_users|zip(path_exists.results)|list }}'
  when: item.1.stat is defined and item.1.stat.exists
  tags:
  - CCE-85629-4
  - DISA-STIG-SLES-15-040090
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict

for home_dir in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $6 }' /etc/passwd); do
    # Only update the permissions when necessary. This will avoid changing the inode timestamp when
    # the permission is already defined as expected, therefore not impacting in possible integrity
    # check systems that also check inodes timestamps.
    find "$home_dir" -maxdepth 0 -perm /7027 -exec chmod u-s,g-w-s,o=- {} \;
done
Group   Configure Syslog   Group contains 1 group and 2 rules
[ref]   The syslog service has been the default Unix logging mechanism for many years. It has a number of downsides, including inconsistent log format, lack of authentication for received messages, and lack of authentication, encryption, or reliable transport for messages sent over a network. However, due to its long history, syslog is a de facto standard which is supported by almost all Unix applications.

In SUSE Linux Enterprise 15, rsyslog has replaced ksyslogd as the syslog daemon of choice, and it includes some additional security features such as reliable, connection-oriented (i.e. TCP) transmission of logs, the option to log to database formats, and the encryption of log data en route to a central logging server. This section discusses how to configure rsyslog for best effect, and how to use tools provided with the system to maintain and monitor logs.
Group   systemd-journald   Group contains 2 rules
[ref]   systemd-journald is a system service that collects and stores logging data. It creates and maintains structured, indexed journals based on logging information that is received from a variety of sources. For more information on systemd-journald and additional systemd-journald configuration options, see https://systemd.io/.

Rule   Ensure journald is configured to compress large log files   [ref]

The journald system can compress large log files to avoid fill the system disk.
Rationale:
Log files that are not properly compressed run the risk of growing so large that they fill up the log partition. Valuable logging information could be lost if the log partition becomes full.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_journald_compress
Identifiers:

CCE-91377-2

References:
cis4.2.2.2

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Ensure journald is configured to compress large log files - Search for a section
    in files
  ansible.builtin.find:
    paths: '{{item.path}}'
    patterns: '{{item.pattern}}'
    contains: ^\s*\[Journal\]
    read_whole_file: true
    use_regex: true
  register: systemd_dropin_files_with_section
  loop:
  - path: '{{ ''/etc/systemd/journald.conf'' | dirname }}'
    pattern: '{{ ''/etc/systemd/journald.conf'' | basename | regex_escape }}'
  - path: /etc/systemd/journal.d
    pattern: .*\.conf
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91377-2
  - journald_compress
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure journald is configured to compress large log files - Count number of
    files which contain the correct section
  ansible.builtin.set_fact:
    count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
      | map(attribute=''matched'') | list | map(''int'') | sum}}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91377-2
  - journald_compress
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure journald is configured to compress large log files - Add missing configuration
    to correct section
  ini_file:
    path: '{{item}}'
    section: Journal
    option: Compress
    value: 'yes'
    state: present
    no_extra_spaces: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - count_of_systemd_dropin_files_with_section | int > 0
  loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
    | map(attribute=''path'') | list }}'
  tags:
  - CCE-91377-2
  - journald_compress
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure journald is configured to compress large log files - Add configuration
    to new remediation file
  ini_file:
    path: /etc/systemd/journal.d/complianceascode_hardening.conf
    section: Journal
    option: Compress
    value: 'yes'
    state: present
    no_extra_spaces: true
    create: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - count_of_systemd_dropin_files_with_section | int == 0
  tags:
  - CCE-91377-2
  - journald_compress
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

found=false

# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf"); do
    if [ ! -e "$f" ]; then
        continue
    fi

    # find key in section and change value
    if grep -qzosP "[[:space:]]*\[Journal\]([^\n\[]*\n+)+?[[:space:]]*Compress" "$f"; then

            sed -i "s/Compress[^(\n)]*/Compress=yes/" "$f"

            found=true

    # find section and add key = value to it
    elif grep -qs "[[:space:]]*\[Journal\]" "$f"; then

            sed -i "/[[:space:]]*\[Journal\]/a Compress=yes" "$f"

            found=true
    fi
done

# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
    file=$(echo "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf" | cut -f1 -d ' ')
    mkdir -p "$(dirname "$file")"

    echo -e "[Journal]\nCompress=yes" >> "$file"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure journald is configured to write log files to persistent disk   [ref]

The journald system may store log files in volatile memory or locally on disk. If the logs are only stored in volatile memory they will we lost upon reboot.
Rationale:
Log files contain valuable data and need to be persistent to aid in possible investigations.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_journald_storage
Identifiers:

CCE-91378-0

References:
cis4.2.2.3

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Ensure journald is configured to write log files to persistent disk - Search
    for a section in files
  ansible.builtin.find:
    paths: '{{item.path}}'
    patterns: '{{item.pattern}}'
    contains: ^\s*\[Journal\]
    read_whole_file: true
    use_regex: true
  register: systemd_dropin_files_with_section
  loop:
  - path: '{{ ''/etc/systemd/journald.conf'' | dirname }}'
    pattern: '{{ ''/etc/systemd/journald.conf'' | basename | regex_escape }}'
  - path: /etc/systemd/journal.d
    pattern: .*\.conf
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91378-0
  - journald_storage
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure journald is configured to write log files to persistent disk - Count
    number of files which contain the correct section
  ansible.builtin.set_fact:
    count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
      | map(attribute=''matched'') | list | map(''int'') | sum}}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91378-0
  - journald_storage
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure journald is configured to write log files to persistent disk - Add
    missing configuration to correct section
  ini_file:
    path: '{{item}}'
    section: Journal
    option: Storage
    value: persistent
    state: present
    no_extra_spaces: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - count_of_systemd_dropin_files_with_section | int > 0
  loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
    | map(attribute=''path'') | list }}'
  tags:
  - CCE-91378-0
  - journald_storage
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure journald is configured to write log files to persistent disk - Add
    configuration to new remediation file
  ini_file:
    path: /etc/systemd/journal.d/complianceascode_hardening.conf
    section: Journal
    option: Storage
    value: persistent
    state: present
    no_extra_spaces: true
    create: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - count_of_systemd_dropin_files_with_section | int == 0
  tags:
  - CCE-91378-0
  - journald_storage
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

found=false

# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf"); do
    if [ ! -e "$f" ]; then
        continue
    fi

    # find key in section and change value
    if grep -qzosP "[[:space:]]*\[Journal\]([^\n\[]*\n+)+?[[:space:]]*Storage" "$f"; then

            sed -i "s/Storage[^(\n)]*/Storage=persistent/" "$f"

            found=true

    # find section and add key = value to it
    elif grep -qs "[[:space:]]*\[Journal\]" "$f"; then

            sed -i "/[[:space:]]*\[Journal\]/a Storage=persistent" "$f"

            found=true
    fi
done

# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
    file=$(echo "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf" | cut -f1 -d ' ')
    mkdir -p "$(dirname "$file")"

    echo -e "[Journal]\nStorage=persistent" >> "$file"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Configuration and Firewalls   Group contains 1 group and 2 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   Uncommon Network Protocols   Group contains 2 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 DCCP Support   [ref]

The Datagram Congestion Control Protocol (DCCP) is a relatively new transport layer protocol, designed to support streaming media and telephony. To configure the system to prevent the dccp kernel module from being loaded, add the following line to the file /etc/modprobe.d/dccp.conf:
install dccp /bin/true
Rationale:
Disabling DCCP protects the system against exploitation of any flaws in its implementation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_dccp_disabled
Identifiers:

CCE-91241-0

References:
cis-csc11, 14, 3, 9
cjis5.10.1
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui3.4.6
disaCCI-001958
isa-62443-20094.3.3.5.1, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistCM-7(a), CM-7(b), CM-6(a)
nist-csfPR.IP-1, PR.PT-3
pcidssReq-1.4.2
os-srgSRG-OS-000096-GPOS-00050, SRG-OS-000378-GPOS-00163
cis3.4.1
pcidss41.4.2

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'dccp' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/dccp.conf
    regexp: install\s+dccp
    line: install dccp /bin/false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91241-0
  - 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)
  - PCI-DSS-Req-1.4.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - kernel_module_dccp_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

- name: Ensure kernel module 'dccp' is blacklisted
  lineinfile:
    create: true
    dest: /etc/modprobe.d/dccp.conf
    regexp: ^blacklist dccp$
    line: blacklist dccp
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91241-0
  - 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)
  - PCI-DSS-Req-1.4.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - kernel_module_dccp_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install dccp" /etc/modprobe.d/dccp.conf ; then
	
	sed -i 's#^install dccp.*#install dccp /bin/false#g' /etc/modprobe.d/dccp.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/dccp.conf
	echo "install dccp /bin/false" >> /etc/modprobe.d/dccp.conf
fi

if ! LC_ALL=C grep -q -m 1 "^blacklist dccp$" /etc/modprobe.d/dccp.conf ; then
	echo "blacklist dccp" >> /etc/modprobe.d/dccp.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

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 the file /etc/modprobe.d/sctp.conf:
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:

CCE-91242-8

References:
cis-csc11, 14, 3, 9
cjis5.10.1
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui3.4.6
disaCCI-000381, CCI-000366
isa-62443-20094.3.3.5.1, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistCM-7(a), CM-7(b), CM-6(a)
nist-csfPR.IP-1, PR.PT-3
pcidssReq-1.4.2
os-srgSRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227
cis3.4.2
pcidss41.4.2

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: install\s+sctp
    line: install sctp /bin/false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91242-8
  - 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)
  - PCI-DSS-Req-1.4.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - kernel_module_sctp_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

- name: Ensure kernel module 'sctp' is blacklisted
  lineinfile:
    create: true
    dest: /etc/modprobe.d/sctp.conf
    regexp: ^blacklist sctp$
    line: blacklist sctp
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91242-8
  - 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)
  - PCI-DSS-Req-1.4.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - kernel_module_sctp_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install sctp" /etc/modprobe.d/sctp.conf ; then
	
	sed -i 's#^install sctp.*#install sctp /bin/false#g' /etc/modprobe.d/sctp.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/sctp.conf
	echo "install sctp /bin/false" >> /etc/modprobe.d/sctp.conf
fi

if ! LC_ALL=C grep -q -m 1 "^blacklist sctp$" /etc/modprobe.d/sctp.conf ; then
	echo "blacklist sctp" >> /etc/modprobe.d/sctp.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   File Permissions and Masks   Group contains 6 groups and 8 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 SUSE Linux Enterprise 15 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 groups and 4 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   Verify Permissions on Files with Local Account Information and Credentials   Group contains 3 rules

Rule   Verify Permissions and Ownership of Old Passwords File   [ref]

To properly set the owner of /etc/security/opasswd, run the command:
$ sudo chown root /etc/security/opasswd 
To properly set the group owner of /etc/security/opasswd, run the command:
$ sudo chgrp root /etc/security/opasswd
To properly set the permissions of /etc/security/opasswd, run the command:
$ sudo chmod 0600 /etc/security/opasswd
Rationale:
The /etc/security/opasswd file stores old passwords to prevent password reuse. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_etc_security_opasswd
Identifiers:

CCE-85572-6

References:
disaCCI-000200
os-srgSRG-OS-000077-GPOS-00045
stigidSLES-15-020240
stigrefSV-234893r622137_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Ensure /etc/security/opasswd exist and has the correct permissions
  file:
    path: /etc/security/opasswd
    owner: root
    group: root
    mode: 384
    state: touch
  tags:
  - CCE-85572-6
  - DISA-STIG-SLES-15-020240
  - file_etc_security_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


# Create /etc/security/opasswd if needed
# Owner group mode root.root 0600
[ -f  /etc/security/opasswd ] || touch /etc/security/opasswd
chown root:root /etc/security/opasswd
chmod 0600 /etc/security/opasswd

Rule   Verify Permissions on Backup shadow File   [ref]

To properly set the permissions of /etc/shadow-, run the command:
$ sudo chmod 0640 /etc/shadow-
Rationale:
The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_shadow
Identifiers:

CCE-91328-5

References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
cis6.1.6
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/shadow-
  stat:
    path: /etc/shadow-
  register: file_exists
  tags:
  - CCE-91328-5
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/shadow-
  file:
    path: /etc/shadow-
    mode: u-xs,g-xws,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CCE-91328-5
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure





chmod u-xs,g-xws,o-xwrt /etc/shadow-

Rule   Verify Permissions on shadow File   [ref]

To properly set the permissions of /etc/shadow, run the command:
$ sudo chmod 0640 /etc/shadow
Rationale:
The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_shadow
Identifiers:

CCE-85804-3

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2.2
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
disaCCI-002223
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
cis6.1.3
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CCE-85804-3
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/shadow
  file:
    path: /etc/shadow
    mode: u-xs,g-xws,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CCE-85804-3
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure





chmod u-xs,g-xws,o-xwrt /etc/shadow
Group   Verify File Permissions Within Some Important Directories   Group contains 1 rule
[ref]   Some directories contain files whose confidentiality or integrity is notably important and may also be susceptible to misconfiguration over time, particularly if unpackaged software is installed. As such, an argument exists to verify that files' permissions within these directories remain configured correctly and restrictively.

Rule   Verify that system commands files are group owned by root or a system account   [ref]

System commands files are stored in the following directories by default:
/bin
/sbin
/usr/bin
/usr/sbin
/usr/local/bin
/usr/local/sbin
All files in these directories should be owned by the root group, or a system account. If the directory, or any file in these directories, is found to be owned by a group other than root or a a system account correct its ownership with the following command:
$ sudo chgrp root FILE
         
Rationale:
If the operating system allows any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupownership_system_commands_dirs
Identifiers:

CCE-85742-5

References:
disaCCI-001499
nistCM-5(6), CM-5(6).1
os-srgSRG-OS-000259-GPOS-00100
stigidSLES-15-010361
anssiR50
stigrefSV-234844r833003_rule

Complexity:medium
Disruption:medium
Reboot:false
Strategy:restrict
- name: Retrieve the system command files and set their group ownership to root
  command: find -L {{ item }}  ! -group root -type f -exec chgrp root '{}' \;
  with_items:
  - /bin
  - /sbin
  - /usr/bin
  - /usr/sbin
  - /usr/local/bin
  - /usr/local/sbin
  changed_when: false
  failed_when: false
  check_mode: false
  tags:
  - CCE-85742-5
  - DISA-STIG-SLES-15-010361
  - NIST-800-53-CM-5(6)
  - NIST-800-53-CM-5(6).1
  - file_groupownership_system_commands_dirs
  - medium_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


for SYSCMDFILES in /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin
do
   find -L $SYSCMDFILES \! -group root -type f -exec chgrp root '{}' \;
done
Group   Restrict Dynamic Mounting and Unmounting of Filesystems   Group contains 3 rules
[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 squashfs   [ref]

To configure the system to prevent the squashfs kernel module from being loaded, add the following line to the file /etc/modprobe.d/squashfs.conf:
install squashfs /bin/true
This effectively prevents usage of this uncommon filesystem. The squashfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems (similar to cramfs). A squashfs 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 system.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_squashfs_disabled
Identifiers:

CCE-92452-2

References:
cis-csc11, 14, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui3.4.6
isa-62443-20094.3.3.5.1, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistCM-7(a), CM-7(b), CM-6(a)
nist-csfPR.IP-1, PR.PT-3
cis1.1.1.1

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'squashfs' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/squashfs.conf
    regexp: install\s+squashfs
    line: install squashfs /bin/false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-92452-2
  - 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_squashfs_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

- name: Ensure kernel module 'squashfs' is blacklisted
  lineinfile:
    create: true
    dest: /etc/modprobe.d/squashfs.conf
    regexp: ^blacklist squashfs$
    line: blacklist squashfs
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-92452-2
  - 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_squashfs_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install squashfs" /etc/modprobe.d/squashfs.conf ; then
	
	sed -i 's#^install squashfs.*#install squashfs /bin/false#g' /etc/modprobe.d/squashfs.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/squashfs.conf
	echo "install squashfs /bin/false" >> /etc/modprobe.d/squashfs.conf
fi

if ! LC_ALL=C grep -q -m 1 "^blacklist squashfs$" /etc/modprobe.d/squashfs.conf ; then
	echo "blacklist squashfs" >> /etc/modprobe.d/squashfs.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Mounting of udf   [ref]

To configure the system to prevent the udf kernel module from being loaded, add the following line to the file /etc/modprobe.d/udf.conf:
install udf /bin/true
This effectively prevents usage of this uncommon filesystem. The udf filesystem type is the universal disk format used to implement the ISO/IEC 13346 and ECMA-167 specifications. This is an open vendor filesystem type for data storage on a broad range of media. This filesystem type is neccessary to support writing DVDs and newer optical disc formats.
Rationale:
Removing support for unneeded filesystem types reduces the local attack surface of the system.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_udf_disabled
Identifiers:

CCE-92453-0

References:
cis-csc11, 14, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui3.4.6
isa-62443-20094.3.3.5.1, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistCM-7(a), CM-7(b), CM-6(a)
nist-csfPR.IP-1, PR.PT-3
cis1.1.1.2

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'udf' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/udf.conf
    regexp: install\s+udf
    line: install udf /bin/false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-92453-0
  - 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_udf_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

- name: Ensure kernel module 'udf' is blacklisted
  lineinfile:
    create: true
    dest: /etc/modprobe.d/udf.conf
    regexp: ^blacklist udf$
    line: blacklist udf
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-92453-0
  - 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_udf_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install udf" /etc/modprobe.d/udf.conf ; then
	
	sed -i 's#^install udf.*#install udf /bin/false#g' /etc/modprobe.d/udf.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/udf.conf
	echo "install udf /bin/false" >> /etc/modprobe.d/udf.conf
fi

if ! LC_ALL=C grep -q -m 1 "^blacklist udf$" /etc/modprobe.d/udf.conf ; then
	echo "blacklist udf" >> /etc/modprobe.d/udf.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Modprobe Loading of USB Storage Driver   [ref]

To prevent USB storage devices from being used, configure the kernel module loading system to prevent automatic loading of the USB storage driver. To configure the system to prevent the usb-storage kernel module from being loaded, add the following line to the file /etc/modprobe.d/usb-storage.conf:
install usb-storage /bin/true
This will prevent the modprobe program from loading the usb-storage module, but will not prevent an administrator (or another program) from using the insmod program to load the module manually.
Rationale:
USB storage devices such as thumb drives can be used to introduce malicious software.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_usb-storage_disabled
Identifiers:

CCE-83294-9

References:
cis-csc1, 12, 15, 16, 5
cobit5APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.1.21
disaCCI-000366, CCI-000778, CCI-001958
hipaa164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b)
isa-62443-20094.3.3.2.2, 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
isa-62443-2013SR 1.1, SR 1.10, SR 1.13, 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 2.6
iso27001-2013A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, 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
nistCM-7(a), CM-7(b), CM-6(a), MP-7
nist-csfPR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7
os-srgSRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
app-srg-ctrSRG-APP-000141-CTR-000315
stigidSLES-15-010480
cis1.1.23
pcidss43.4.2
stigrefSV-234856r854202_rule

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'usb-storage' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/usb-storage.conf
    regexp: install\s+usb-storage
    line: install usb-storage /bin/false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83294-9
  - DISA-STIG-SLES-15-010480
  - NIST-800-171-3.1.21
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - PCI-DSSv4-3.4.2
  - disable_strategy
  - kernel_module_usb-storage_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

- name: Ensure kernel module 'usb-storage' is blacklisted
  lineinfile:
    create: true
    dest: /etc/modprobe.d/usb-storage.conf
    regexp: ^blacklist usb-storage$
    line: blacklist usb-storage
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83294-9
  - DISA-STIG-SLES-15-010480
  - NIST-800-171-3.1.21
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - PCI-DSSv4-3.4.2
  - disable_strategy
  - kernel_module_usb-storage_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install usb-storage" /etc/modprobe.d/usb-storage.conf ; then
	
	sed -i 's#^install usb-storage.*#install usb-storage /bin/false#g' /etc/modprobe.d/usb-storage.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/usb-storage.conf
	echo "install usb-storage /bin/false" >> /etc/modprobe.d/usb-storage.conf
fi

if ! LC_ALL=C grep -q -m 1 "^blacklist usb-storage$" /etc/modprobe.d/usb-storage.conf ; then
	echo "blacklist usb-storage" >> /etc/modprobe.d/usb-storage.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Restrict Programs from Dangerous Execution Patterns   Group contains 1 group and 1 rule
[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   Disable Core Dumps   Group contains 1 rule
[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 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: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_disable_users_coredumps
Identifiers:

CCE-85740-9

References:
cis-csc1, 12, 13, 15, 16, 2, 7, 8
cobit5APO13.01, BAI04.04, DSS01.03, DSS03.05, DSS05.07
disaCCI-000366
isa-62443-2013SR 6.2, SR 7.1, SR 7.2
iso27001-2013A.12.1.3, A.17.2.1
nistCM-6, SC-7(10)
nist-csfDE.CM-1, PR.DS-4
os-srgSRG-OS-000480-GPOS-00227
cis1.6.1
pcidss43.3.1.1

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85740-9
  - NIST-800-53-CM-6
  - NIST-800-53-SC-7(10)
  - PCI-DSSv4-3.3.1.1
  - disable_users_coredumps
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Disable core dumps with limits
  lineinfile:
    dest: /etc/security/limits.conf
    regexp: ^[^#].*core
    line: '*        hard       core      0'
    create: true
  when: '"pam" in ansible_facts.packages'
  tags:
  - CCE-85740-9
  - NIST-800-53-CM-6
  - NIST-800-53-SC-7(10)
  - PCI-DSSv4-3.3.1.1
  - disable_users_coredumps
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

SECURITY_LIMITS_FILE="/etc/security/limits.conf"

if grep -qE '^\s*\*\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

if ls /etc/security/limits.d/*.conf > /dev/null; then
        sed -ri '/^\s*\*\s+hard\s+core/d' /etc/security/limits.d/*.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Services   Group contains 4 groups and 23 rules
[ref]   The best protection against vulnerable software is running less software. This section describes how to review the software which SUSE Linux Enterprise 15 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default SUSE Linux Enterprise 15 system and provides guidance about which ones can be safely disabled.

SUSE Linux Enterprise 15 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building SUSE Linux Enterprise 15 systems, it is highly recommended to select the minimal packages and then build up the system from there.
Group   Cron and At Daemons   Group contains 5 rules
[ref]   The cron and at services are used to allow commands to be executed at a later time. The cron service is required by almost all systems to perform necessary maintenance tasks, while at may or may not be required on a given system. Both daemons should be configured defensively.

Rule   Verify Permissions on cron.d   [ref]

To properly set the permissions of /etc/cron.d, run the command:
$ sudo chmod 0700 /etc/cron.d
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_d
Identifiers:

CCE-91304-6

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
os-srgSRG-OS-000480-GPOS-00227
cis5.1.7
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/cron.d/ file(s)
  command: 'find -H /etc/cron.d/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt  -type d '
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91304-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for /etc/cron.d/ file(s)
  file:
    path: '{{ item }}'
    mode: u-s,g-xwrs,o-xwrt
    state: directory
  with_items:
  - '{{ files_found.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91304-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.d/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.daily   [ref]

To properly set the permissions of /etc/cron.daily, run the command:
$ sudo chmod 0700 /etc/cron.daily
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_daily
Identifiers:

CCE-91301-2

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
os-srgSRG-OS-000480-GPOS-00227
cis5.1.4
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/cron.daily/ file(s)
  command: 'find -H /etc/cron.daily/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt  -type d '
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91301-2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_daily
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for /etc/cron.daily/ file(s)
  file:
    path: '{{ item }}'
    mode: u-s,g-xwrs,o-xwrt
    state: directory
  with_items:
  - '{{ files_found.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91301-2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_daily
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.daily/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.hourly   [ref]

To properly set the permissions of /etc/cron.hourly, run the command:
$ sudo chmod 0700 /etc/cron.hourly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_hourly
Identifiers:

CCE-91300-4

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
os-srgSRG-OS-000480-GPOS-00227
cis5.1.3
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/cron.hourly/ file(s)
  command: 'find -H /etc/cron.hourly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt  -type
    d '
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91300-4
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_hourly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for /etc/cron.hourly/ file(s)
  file:
    path: '{{ item }}'
    mode: u-s,g-xwrs,o-xwrt
    state: directory
  with_items:
  - '{{ files_found.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91300-4
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_hourly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.hourly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.monthly   [ref]

To properly set the permissions of /etc/cron.monthly, run the command:
$ sudo chmod 0700 /etc/cron.monthly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_monthly
Identifiers:

CCE-91303-8

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
os-srgSRG-OS-000480-GPOS-00227
cis5.1.6
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/cron.monthly/ file(s)
  command: 'find -H /etc/cron.monthly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt  -type
    d '
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91303-8
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_monthly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for /etc/cron.monthly/ file(s)
  file:
    path: '{{ item }}'
    mode: u-s,g-xwrs,o-xwrt
    state: directory
  with_items:
  - '{{ files_found.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91303-8
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_monthly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.monthly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.weekly   [ref]

To properly set the permissions of /etc/cron.weekly, run the command:
$ sudo chmod 0700 /etc/cron.weekly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_weekly
Identifiers:

CCE-91302-0

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
os-srgSRG-OS-000480-GPOS-00227
cis5.1.5
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Find /etc/cron.weekly/ file(s)
  command: 'find -H /etc/cron.weekly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt  -type
    d '
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91302-0
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_weekly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for /etc/cron.weekly/ file(s)
  file:
    path: '{{ item }}'
    mode: u-s,g-xwrs,o-xwrt
    state: directory
  with_items:
  - '{{ files_found.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91302-0
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_weekly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.weekly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Time Protocol   Group contains 1 rule
[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/latest/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 https://chrony-project.org/documentation.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   Ensure that chronyd is running under chrony user account   [ref]

chrony is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at https://chrony-project.org/. Chrony can be configured to be a client and/or a server. To ensure that chronyd is running under chrony user account, add or edit the OPTIONS variable in /etc/sysconfig/chronyd to include -u chrony:
OPTIONS="-u chrony"
This recommendation only applies if chrony is in use on the system.
Rationale:
If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_run_as_chrony_user
Identifiers:

CCE-91360-8

References:
cis2.2.1.3
pcidss410.6.3

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q chrony; }; then

if grep -q 'OPTIONS=.*' /etc/sysconfig/chronyd; then
	# trying to solve cases where the parameter after OPTIONS
	#may or may not be enclosed in quotes
	sed -i -E -e 's/\s*-u\s*\w+\s*/ /' -e 's/^([\s]*OPTIONS=["]?[^"]*)("?)/\1 -u chrony\2/' /etc/sysconfig/chronyd
else
	echo 'OPTIONS="-u chrony"' >> /etc/sysconfig/chronyd
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   SSH Server   Group contains 1 group and 17 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 16 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 Count Max to zero   [ref]

The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. To ensure the SSH timeout occurs precisely when the ClientAliveInterval is set, set the ClientAliveCountMax to value of 0 in /etc/ssh/sshd_config:
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_0
Identifiers:

CCE-83284-0

References:
cis-csc1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis5.5.6
cobit5APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.1.11
disaCCI-000879, CCI-001133, CCI-002361
hipaa164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-20094.3.3.2.2, 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
isa-62443-2013SR 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
iso27001-2013A.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
nerc-cipCIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nistAC-2(5), AC-12, AC-17(a), SC-10, CM-6(a)
nist-csfDE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2
pcidssReq-8.1.8
os-srgSRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
stigidSLES-15-010320
stigrefSV-234830r951636_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Set SSH Client Alive Count Max to zero
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveCountMax\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveCountMax\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveCountMax\s+
      line: ClientAliveCountMax 0
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83284-0
  - CJIS-5.5.6
  - DISA-STIG-SLES-15-010320
  - 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
  - PCI-DSS-Req-8.1.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_keepalive_0

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

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
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "ClientAliveCountMax 0" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH Client Alive Interval   [ref]

SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out.

To set this timeout interval, edit the following line in /etc/ssh/sshd_config as follows:
ClientAliveInterval 600
        


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.
Warning:  SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration.
Warning:  Following conditions may prevent the SSH session to time out:
  • Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
  • Any scp or sftp activity by the same user to the host resets the timeout.
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:

CCE-83281-6

References:
cis-csc1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis5.5.6
cobit5APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.1.11
disaCCI-000879, CCI-001133, CCI-002361
isa-62443-20094.3.3.2.2, 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
isa-62443-2013SR 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
iso27001-2013A.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
nerc-cipCIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nistCM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a)
nist-csfDE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2
pcidssReq-8.1.8
os-srgSRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175
stigidSLES-15-010280
cis5.2.16
pcidss48.2.8
stigrefSV-234827r951634_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value sshd_idle_timeout_value # promote to variable
  set_fact:
    sshd_idle_timeout_value: !!str 600
  tags:
    - always

- name: Set SSH Client Alive Interval
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveInterval\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveInterval\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveInterval\s+
      line: ClientAliveInterval {{ sshd_idle_timeout_value }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83281-6
  - CJIS-5.5.6
  - DISA-STIG-SLES-15-010280
  - 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
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_idle_timeout

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

sshd_idle_timeout_value='600'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable SSH TCP Forwarding   [ref]

The AllowTcpForwarding parameter specifies whether TCP forwarding is permitted. To disable TCP forwarding, add or correct the following line in /etc/ssh/sshd_config:
AllowTcpForwarding no
Rationale:
Leaving port forwarding enabled can expose the organization to security risks and back-doors.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_tcp_forwarding
Identifiers:

CCE-91334-3

References:
cis5.2.20
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Disable SSH TCP Forwarding
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*AllowTcpForwarding\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*AllowTcpForwarding\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*AllowTcpForwarding\s+
      line: AllowTcpForwarding no
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91334-3
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_tcp_forwarding

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "AllowTcpForwarding no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable SSH Support for User Known Hosts   [ref]

SSH can allow system users to connect to systems if a cache of the remote systems public keys is available. This should be disabled.

To ensure this behavior is disabled, add or correct the following line in /etc/ssh/sshd_config:
IgnoreUserKnownHosts yes
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: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_user_known_hosts
Identifiers:

CCE-85642-7

References:
cis-csc11, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05
cui3.1.12
disaCCI-000366
hipaa164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-20094.3.4.3.2, 4.3.4.3.3
isa-62443-2013SR 7.6
iso27001-2013A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4
nistAC-17(a), CM-7(a), CM-7(b), CM-6(a)
nist-csfPR.IP-1
osppFIA_UAU.1
os-srgSRG-OS-000480-GPOS-00227
stigidSLES-15-040230
stigrefSV-235007r951642_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Disable SSH Support for User Known Hosts
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*IgnoreUserKnownHosts\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*IgnoreUserKnownHosts\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*IgnoreUserKnownHosts\s+
      line: IgnoreUserKnownHosts yes
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85642-7
  - DISA-STIG-SLES-15-040230
  - 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_user_known_hosts

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*IgnoreUserKnownHosts\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "IgnoreUserKnownHosts yes" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable X11 Forwarding   [ref]

The X11Forwarding parameter provides the ability to tunnel X11 traffic through the connection to enable remote graphic connections. SSH has the capability to encrypt remote X11 connections when SSH's X11Forwarding option is enabled.
The default SSH configuration disables X11Forwarding. The appropriate configuration is used if no value is set for X11Forwarding.
To explicitly disable X11 Forwarding, add or correct the following line in /etc/ssh/sshd_config:
X11Forwarding no
Rationale:
Disable X11 forwarding unless there is an operational requirement to use X11 applications directly. There is a small risk that the remote X11 servers of users who are logged in via SSH with X11 forwarding could be compromised by other users on the X11 server. Note that even if X11 forwarding is disabled, users can always install their own forwarders.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_x11_forwarding
Identifiers:

CCE-85707-8

References:
disaCCI-000366
nistCM-6.1(iv)
os-srgSRG-OS-000480-GPOS-00227
stigidSLES-15-040290
cis5.2.6
pcidss42.2.6
stigrefSV-235013r951646_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Disable X11 Forwarding
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*X11Forwarding\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*X11Forwarding\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*X11Forwarding\s+
      line: X11Forwarding no
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85707-8
  - DISA-STIG-SLES-15-040290
  - NIST-800-53-CM-6.1(iv)
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_x11_forwarding

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "X11Forwarding no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

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:

CCE-83263-4

References:
cis-csc1, 12, 15, 16
cjis5.5.6
cobit5DSS05.04, DSS05.10, DSS06.10
cui3.1.9
disaCCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388
hipaa164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-20094.3.3.6.1, 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
isa-62443-2013SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nistAC-8(a), AC-8(c), AC-17(a), CM-6(a)
nist-csfPR.AC-7
osppFTA_TAB.1
pcidssReq-2.2.4
os-srgSRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
stigidSLES-15-010040
cis5.2.18
stigrefSV-234805r951626_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Enable SSH Warning Banner
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*Banner\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*Banner\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*Banner\s+
      line: Banner /etc/issue
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83263-4
  - CJIS-5.5.6
  - DISA-STIG-SLES-15-010040
  - 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)
  - PCI-DSS-Req-2.2.4
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_enable_warning_banner

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

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
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "Banner /etc/issue" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH Daemon LogLevel to VERBOSE   [ref]

The VERBOSE parameter configures the SSH daemon to record login and logout activity. To specify the log level in SSH, add or correct the following line in /etc/ssh/sshd_config:
LogLevel VERBOSE
Rationale:
SSH provides several logging levels with varying amounts of verbosity. DEBUG is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information. INFO or VERBOSE level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_loglevel_verbose
Identifiers:

CCE-83270-9

References:
disaCCI-000067
nerc-cipCIP-007-3 R7.1
nistAC-17(a), AC-17(1), CM-6(a)
pcidssReq-2.2.4
os-srgSRG-OS-000032-GPOS-00013
stigidSLES-15-010150
cis5.2.5
pcidss42.2.6
stigrefSV-234815r951628_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Set SSH Daemon LogLevel to VERBOSE
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*LogLevel\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*LogLevel\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*LogLevel\s+
      line: LogLevel VERBOSE
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83270-9
  - DISA-STIG-SLES-15-010150
  - NIST-800-53-AC-17(1)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_loglevel_verbose

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "LogLevel VERBOSE" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH authentication attempt limit   [ref]

The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. Once the number of failures reaches half this value, additional failures are logged. to set MaxAUthTries edit /etc/ssh/sshd_config as follows:
MaxAuthTries 4
        
Rationale:
Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_max_auth_tries
Identifiers:

CCE-91332-7

References:
ism0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
cis5.2.7
pcidss42.2.6

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

- name: Set SSH authentication attempt limit
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxAuthTries\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxAuthTries\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxAuthTries\s+
      line: MaxAuthTries {{ sshd_max_auth_tries_value }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91332-7
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_max_auth_tries

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

sshd_max_auth_tries_value='4'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*MaxAuthTries\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MaxAuthTries $sshd_max_auth_tries_value" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH MaxSessions limit   [ref]

The MaxSessions parameter specifies the maximum number of open sessions permitted from a given connection. To set MaxSessions edit /etc/ssh/sshd_config as follows:
MaxSessions 10
        
Rationale:
To protect a system from denial of service due to a large number of concurrent sessions, use the rate limiting function of MaxSessions to protect availability of sshd logins and prevent overwhelming the daemon.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_max_sessions
Identifiers:

CCE-91309-5

References:
cis5.2.22
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: XCCDF Value var_sshd_max_sessions # promote to variable
  set_fact:
    var_sshd_max_sessions: !!str 10
  tags:
    - always

- name: Set SSH MaxSessions limit
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxSessions\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxSessions\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxSessions\s+
      line: MaxSessions {{ var_sshd_max_sessions }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91309-5
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sshd_set_max_sessions

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_sshd_max_sessions='10'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*MaxSessions\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MaxSessions $var_sshd_max_sessions" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure SSH MaxStartups is configured   [ref]

The MaxStartups parameter specifies the maximum number of concurrent unauthenticated connections to the SSH daemon. Additional connections will be dropped until authentication succeeds or the LoginGraceTime expires for a connection. To confgure MaxStartups, you should add or correct the following line in the /etc/ssh/sshd_config file:
MaxStartups 10:30:100
        
CIS recommends a MaxStartups value of '10:30:60', or more restrictive where dictated by site policy.
Rationale:
To protect a system from denial of service due to a large number of pending authentication connection attempts, use the rate limiting function of MaxStartups to protect availability of sshd logins and prevent overwhelming the daemon.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_maxstartups
Identifiers:

CCE-91308-7

References:
cis5.2.21
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value var_sshd_set_maxstartups # promote to variable
  set_fact:
    var_sshd_set_maxstartups: !!str 10:30:100
  tags:
    - always

- name: Ensure SSH MaxStartups is configured
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxStartups\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxStartups\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxStartups\s+
      line: MaxStartups {{ var_sshd_set_maxstartups }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91308-7
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_maxstartups

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_sshd_set_maxstartups='10:30:100'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*MaxStartups\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MaxStartups $var_sshd_set_maxstartups" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Use Only FIPS 140-2 Validated Ciphers   [ref]

Limit the ciphers to those algorithms which are FIPS-approved. Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode. The following line in /etc/ssh/sshd_config demonstrates use of FIPS-approved ciphers:
Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
The man page sshd_config(5) contains a list of supported ciphers. The rule is parametrized to use the following ciphers: aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se.
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:
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and system data may be compromised.
Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules.
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 SUSE Linux Enterprise 15.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_use_approved_ciphers
Identifiers:

CCE-91337-6

References:
cis-csc1, 11, 12, 14, 15, 16, 18, 3, 5, 6, 8, 9
cjis5.5.6
cobit5APO11.04, APO13.01, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, MEA02.01
cui3.1.13, 3.13.11, 3.13.8
disaCCI-000068, CCI-000366, CCI-000803, CCI-000877, CCI-002890, CCI-003123
hipaa164.308(b)(1), 164.308(b)(2), 164.312(e)(1), 164.312(e)(2)(i), 164.312(e)(2)(ii), 164.314(b)(2)(i)
isa-62443-20094.3.3.2.2, 4.3.3.3.9, 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, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013SR 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
iso27001-2013A.11.2.6, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, 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.18.1.4, A.6.1.2, A.6.2.1, A.6.2.2, 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
nistCM-6(a), AC-17(a), AC-17(2), SC-13, MA-4(6), IA-5(1)(c), SC-12(2), SC-12(3)
nist-csfPR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-1, PR.PT-1, PR.PT-3, PR.PT-4
os-srgSRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174
stigidSLES-15-010160
cis5.2.13
pcidss42.2.7
stigrefSV-234816r951630_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value sshd_approved_ciphers # promote to variable
  set_fact:
    sshd_approved_ciphers: !!str aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se
  tags:
    - always

- name: Use Only FIPS 140-2 Validated Ciphers
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*Ciphers\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*Ciphers\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*Ciphers\s+
      line: Ciphers {{ sshd_approved_ciphers }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91337-6
  - CJIS-5.5.6
  - DISA-STIG-SLES-15-010160
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.11
  - NIST-800-171-3.13.8
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - PCI-DSSv4-2.2.7
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_use_approved_ciphers

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

sshd_approved_ciphers='aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se'


# 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' <<< "^Ciphers")

# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$sshd_approved_ciphers"

# 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 -i -e "^Ciphers\\>" "/etc/ssh/sshd_config"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^Ciphers\\>.*/$escaped_formatted_output/gi" "/etc/ssh/sshd_config"
else
    if [[ -s "/etc/ssh/sshd_config" ]] && [[ -n "$(tail -c 1 -- "/etc/ssh/sshd_config" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/ssh/sshd_config"
    fi
    cce="CCE-91337-6"
    printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/ssh/sshd_config" >> "/etc/ssh/sshd_config"
    printf '%s\n' "$formatted_output" >> "/etc/ssh/sshd_config"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Use Only FIPS 140-2 Validated Ciphers   [ref]

Limit the ciphers to those algorithms which are FIPS-approved. The following line in /etc/ssh/sshd_config demonstrates use of FIPS-approved ciphers:
Ciphers aes256-ctr,aes192-ctr,aes128-ctr
This rule ensures that there are configured ciphers mentioned above (or their subset), keeping the given order of algorithms.
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:
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and system data may be compromised.
Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules.
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 SUSE Linux Enterprise 15.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_use_approved_ciphers_ordered_stig
Identifiers:

CCE-83271-7

References:
disaCCI-000068, CCI-000366, CCI-000803, CCI-000877, CCI-002890, CCI-003123
os-srgSRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174
stigidSLES-15-010160
stigrefSV-234816r951630_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Configure sshd to use approved ciphers
  lineinfile:
    path: /etc/ssh/sshd_config
    line: Ciphers aes256-ctr,aes192-ctr,aes128-ctr
    state: present
    regexp: ^[\s]*[Cc]iphers[\s]+(aes256-ctr(?=[\w,-@]+|$),?)?(aes192-ctr(?=[\w,-@]+|$),?)?(aes128-ctr(?=[\w,-@]+|$),?)?[\s]*(?:#.*)?$
    create: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83271-7
  - DISA-STIG-SLES-15-010160
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_use_approved_ciphers_ordered_stig

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if grep -q -P '^\s*[Cc]iphers\s+' /etc/ssh/sshd_config; then
  sed -i 's/^\s*[Cc]iphers.*/Ciphers aes256-ctr,aes192-ctr,aes128-ctr/' /etc/ssh/sshd_config
else
  echo "Ciphers aes256-ctr,aes192-ctr,aes128-ctr" >> /etc/ssh/sshd_config
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Use Only FIPS 140-2 Validated MACs   [ref]

Limit the MACs to those hash algorithms which are FIPS-approved. The following line in /etc/ssh/sshd_config demonstrates use of FIPS-approved MACs:
MACs hmac-sha2-512,hmac-sha2-256
The man page sshd_config(5) contains a list of supported MACs. The rule is parametrized to use the following MACs: hmac-sha2-512,hmac-sha2-256,hmac-sha1,hmac-sha1-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com.
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:
DoD Information Systems are required to use FIPS-approved cryptographic hash functions. The only SSHv2 hash algorithms meeting this requirement is SHA2.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_use_approved_macs
Identifiers:

CCE-91338-4

References:
cis-csc1, 12, 13, 15, 16, 5, 8
cobit5APO01.06, APO13.01, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.07, DSS06.02, DSS06.03
cui3.1.13, 3.13.11, 3.13.8
disaCCI-000068, CCI-000803, CCI-000877, CCI-001453, CCI-003123
hipaa164.308(b)(1), 164.308(b)(2), 164.312(e)(1), 164.312(e)(2)(i), 164.312(e)(2)(ii), 164.314(b)(2)(i)
isa-62443-20094.3.3.5.1, 4.3.3.6.6
isa-62443-2013SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.6, 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
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.11.2.6, 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.6.2.1, A.6.2.2, 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
nistCM-6(a), AC-17(a), AC-17(2), SC-13, MA-4(6), SC-12(2), SC-12(3)
nist-csfPR.AC-1, PR.AC-3, PR.DS-5, PR.PT-4
os-srgSRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000394-GPOS-00174
stigidSLES-15-010270
cis5.2.14
pcidss42.2.7
stigrefSV-234826r951632_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: XCCDF Value sshd_approved_macs # promote to variable
  set_fact:
    sshd_approved_macs: !!str hmac-sha2-512,hmac-sha2-256,hmac-sha1,hmac-sha1-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com
  tags:
    - always

- name: Use Only FIPS 140-2 Validated MACs
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MACs\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MACs\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MACs\s+
      line: MACs {{ sshd_approved_macs }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91338-4
  - DISA-STIG-SLES-15-010270
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.11
  - NIST-800-171-3.13.8
  - 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
  - PCI-DSSv4-2.2.7
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_use_approved_macs

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

sshd_approved_macs='hmac-sha2-512,hmac-sha2-256,hmac-sha1,hmac-sha1-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com'


# 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' <<< "^MACs")

# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$sshd_approved_macs"

# 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 -i -e "^MACs\\>" "/etc/ssh/sshd_config"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^MACs\\>.*/$escaped_formatted_output/gi" "/etc/ssh/sshd_config"
else
    if [[ -s "/etc/ssh/sshd_config" ]] && [[ -n "$(tail -c 1 -- "/etc/ssh/sshd_config" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/ssh/sshd_config"
    fi
    cce="CCE-91338-4"
    printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/ssh/sshd_config" >> "/etc/ssh/sshd_config"
    printf '%s\n' "$formatted_output" >> "/etc/ssh/sshd_config"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Use Only FIPS 140-2 Validated MACs   [ref]

Limit the MACs to those hash algorithms which are FIPS-approved. The following line in /etc/ssh/sshd_config demonstrates use of FIPS-approved MACs:
MACs hmac-sha2-512,hmac-sha2-256
This rule ensures that there are configured MACs mentioned above (or their subset), keeping the given order of algorithms.
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:
DoD Information Systems are required to use FIPS-approved cryptographic hash functions. The only SSHv2 hash algorithms meeting this requirement is SHA2.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_use_approved_macs_ordered_stig
Identifiers:

CCE-83280-8

References:
disaCCI-000068, CCI-000803, CCI-000877, CCI-001453, CCI-003123
os-srgSRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000394-GPOS-00174
stigidSLES-15-010270
stigrefSV-234826r951632_rule

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Configure sshd to use approved MACs
  lineinfile:
    path: /etc/ssh/sshd_config
    line: MACs hmac-sha2-512,hmac-sha2-256
    state: present
    regexp: ^[\s]*MACs[\s]+(hmac-sha2-512(?=[\w,-@]+|$),?)?(hmac-sha2-256(?=[\w,-@]+|$),?)?[\s]*(?:#.*)?$
    create: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-83280-8
  - DISA-STIG-SLES-15-010270
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_use_approved_macs_ordered_stig

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if grep -q -P '^\s*MACs\s+' /etc/ssh/sshd_config; then
  sed -i 's/^\s*MACs.*/MACs hmac-sha2-512,hmac-sha2-256/' /etc/ssh/sshd_config
else
  echo "MACs hmac-sha2-512,hmac-sha2-256" >> /etc/ssh/sshd_config
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on SSH Server config file   [ref]

To properly set the permissions of /etc/ssh/sshd_config, run the command:
$ sudo chmod 0600 /etc/ssh/sshd_config
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_sshd_config
Identifiers:

CCE-91306-1

References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
iso27001-2013A.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
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nistAC-17(a), CM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
os-srgSRG-OS-000480-GPOS-00227
cis5.2.1
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/ssh/sshd_config
  stat:
    path: /etc/ssh/sshd_config
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-91306-1
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/ssh/sshd_config
  file:
    path: /etc/ssh/sshd_config
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CCE-91306-1
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chmod u-xs,g-xwrs,o-xwrt /etc/ssh/sshd_config

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   System Accounting with auditd   Group contains 11 groups and 89 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 Red Hat Enterprise Linux 7 Documentation available at https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/selinux_users_and_administrators_guide/index#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   Configure auditd Rules for Comprehensive Auditing   Group contains 9 groups and 83 rules
[ref]   The auditd program can perform comprehensive monitoring of system activity. This section describes recommended configuration settings for comprehensive auditing, but a full description of the auditing system's capabilities is beyond the scope of this guide. The mailing list linux-audit@redhat.com exists to facilitate community discussion of the auditing system.

The audit subsystem supports extensive collection of events, including:
  • Tracing of arbitrary system calls (identified by name or number) on entry or exit.
  • Filtering by PID, UID, call success, system call argument (with some limitations), etc.
  • Monitoring of specific files for modifications to the file's contents or metadata.

Auditing rules at startup are controlled by the file /etc/audit/audit.rules. Add rules to it to meet the auditing requirements for your organization. Each line in /etc/audit/audit.rules represents a series of arguments that can be passed to auditctl and can be individually tested during runtime. See documentation in /usr/share/doc/audit-VERSION and in the related man pages for more details.

If copying any example audit rulesets from /usr/share/doc/audit-VERSION, be sure to comment out the lines containing arch= which are not appropriate for your system's architecture. Then review and understand the following rules, ensuring rules are activated as needed for the appropriate architecture.

After reviewing all the rules, reading the following sections, and editing as needed, the new rules can be activated as follows:
$ sudo service auditd restart
Group   Record Events that Modify the System's Discretionary Access Controls   Group contains 15 rules
[ref]   At a minimum, the audit system should collect file permission changes for all users and root. Note that the "-F arch=b32" lines should be present even on a 64 bit system. These commands identify system calls for auditing. Even if the system is 64 bit it can still execute 32 bit system calls. Additionally, these rules can be configured in a number of ways while still achieving the desired effect. An example of this is that the "-S" calls could be split up and placed on separate lines, however, this is less efficient. Add the following to /etc/audit/audit.rules:
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b32 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If your system is 64 bit then these lines should be duplicated and the arch=b32 replaced with arch=b64 as follows:
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b64 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

Rule   Record Events that Modify the System's Discretionary Access Controls - chmod   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_chmod
Identifiers:

CCE-85693-0

References:
cis-csc1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis5.4.1.1
cobit5APO10.01, 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
cui3.1.7
disaCCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884
hipaa164.308(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)
isa-62443-20094.2.3.10, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistAU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a)
nist-csfDE.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
osppFAU_GEN.1.1.c
pcidssReq-10.5.5
os-srgSRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
app-srg-ctrSRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
stigidSLES-15-030290
cis4.1.9
anssiR73
pcidss410.3.4
stigrefSV-234928r854238_rule

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85693-0
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit chmod tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( ansible_architecture == "aarch64" )
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CCE-85693-0
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chmod for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( ansible_architecture == "aarch64" )
  tags:
  - CCE-85693-0
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chmod for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( ansible_architecture == "aarch64" )
  - audit_arch == "b64"
  tags:
  - CCE-85693-0
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit && { ! ( grep -q aarch64 /proc/sys/kernel/osrelease ); }; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="chmod"
	KEY="perm_mod"
	SYSCALL_GROUPING="chmod fchmod fchmodat"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()

# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - chown   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_chown
Identifiers:

CCE-85690-6

References:
cis-csc1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis5.4.1.1
cobit5APO10.01, 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
cui3.1.7
disaCCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884
hipaa164.308(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)
isa-62443-20094.2.3.10, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistAU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a)
nist-csfDE.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
osppFAU_GEN.1.1.c
pcidssReq-10.5.5
os-srgSRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
app-srg-ctrSRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
stigidSLES-15-030250
cis4.1.9
anssiR73
pcidss410.3.4
stigrefSV-234924r854236_rule

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85690-6
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030250
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit chown tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( ansible_architecture == "aarch64" )
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CCE-85690-6
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030250
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chown for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( ansible_architecture == "aarch64" )
  tags:
  - CCE-85690-6
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030250
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chown for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( ansible_architecture == "aarch64" )
  - audit_arch == "b64"
  tags:
  - CCE-85690-6
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030250
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit && { ! ( grep -q aarch64 /proc/sys/kernel/osrelease ); }; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="chown"
	KEY="perm_mod"
	SYSCALL_GROUPING="chown fchown fchownat lchown"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()

# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fchmod   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchmod
Identifiers:

CCE-85694-8

References:
cis-csc1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis5.4.1.1
cobit5APO10.01, 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
cui3.1.7
disaCCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884
hipaa164.308(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)
isa-62443-20094.2.3.10, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistAU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a)
nist-csfDE.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
osppFAU_GEN.1.1.c
pcidssReq-10.5.5
os-srgSRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
app-srg-ctrSRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
stigidSLES-15-030290
cis4.1.9
anssiR73
pcidss410.3.4
stigrefSV-234928r854238_rule

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85694-8
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fchmod tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CCE-85694-8
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchmod for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85694-8
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchmod for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CCE-85694-8
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fchmod"
	KEY="perm_mod"
	SYSCALL_GROUPING="chmod fchmod fchmodat"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()

# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fchmodat   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchmodat
Identifiers:

CCE-85695-5

References:
cis-csc1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis5.4.1.1
cobit5APO10.01, 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
cui3.1.7
disaCCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884
hipaa164.308(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)
isa-62443-20094.2.3.10, 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
isa-62443-2013SR 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
iso27001-2013A.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
nistAU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a)
nist-csfDE.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
osppFAU_GEN.1.1.c
pcidssReq-10.5.5
os-srgSRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
app-srg-ctrSRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
stigidSLES-15-030290
cis4.1.9
anssiR73
pcidss410.3.4
stigrefSV-234928r854238_rule

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-85695-5
  - CJIS-5.4.1.1
  - DISA-STIG-SLES-15-030290
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(a)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-12.1(ii)
  - NIST-800-53-AU-12.1(iv)
  - NIST-800-53-AU-3
  - NIST-800-53-AU-3.1
  - NIST-800-53-MA-4(1)(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4