Guide to the Secure Configuration of Alibaba Cloud Linux 3

with profile PCI-DSS v4.0 Control Baseline for Alibaba Cloud Linux 3
Payment Card Industry - Data Security Standard (PCI-DSS) is a set of security standards designed to ensure the secure handling of payment card data, with the goal of preventing data breaches and protecting sensitive financial information.
This guide presents a catalog of security-relevant configuration settings for Alibaba Cloud Linux 3. 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 TitlePCI-DSS v4.0 Control Baseline for Alibaba Cloud Linux 3
Profile IDxccdf_org.ssgproject.content_profile_pci-dss

CPE Platforms

  • cpe:/o:alinux:alibaba_cloud_linux:3

Revision History

Current version: 0.1.74

  • draft (as of 2024-06-20)

Table of Contents

  1. System Settings
    1. Installing and Maintaining Software
    2. Account and Access Control
    3. GRUB2 bootloader configuration
    4. Configure Syslog
    5. Network Configuration and Firewalls
    6. File Permissions and Masks
    7. SELinux
  2. Services
    1. Avahi Server
    2. Cron and At Daemons
    3. Mail Server Software
    4. NFS and RPC
    5. Network Time Protocol
    6. Obsolete Services
    7. 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 Alibaba Cloud Linux 3   Group contains 72 groups and 191 rules
Group   System Settings   Group contains 47 groups and 92 rules
[ref]   Contains rules that check correct system settings.
Group   Installing and Maintaining Software   Group contains 7 groups and 12 rules
[ref]   The following sections contain information on security-relevant choices during the initial operating system installation process and the setup of software updates.
Group   System and Software Integrity   Group contains 4 groups and 6 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 2 groups 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 RPM   Group contains 2 rules
[ref]   The RPM package management system includes the ability to verify the integrity of installed packages by comparing the installed files with information about the files taken from the package metadata stored in the RPM database. Although an attacker could corrupt the RPM database (analogous to attacking the AIDE database as described above), this check can still reveal modification of important files. To list which files on the system differ from what is expected by the RPM database:
$ rpm -qVa
See the man page for rpm to see a complete explanation of each column.

Rule   Verify File Hashes with RPM   [ref]

Without cryptographic integrity protections, system executables and files can be altered by unauthorized users without detection. The RPM package management system can check the hashes of installed software packages, including many that are important to system security. To verify that the cryptographic hash of system files and commands matches vendor values, run the following command to list which files on the system have hashes that differ from what is expected by the RPM database:
$ rpm -Va --noconfig | grep '^..5'
If the file was not expected to change, investigate the cause of the change using audit logs or other means. The package can then be reinstalled to restore the file. Run the following command to determine which package owns the file:
$ rpm -qf FILENAME
          
The package can be reinstalled from a yum repository using the command:
$ sudo yum reinstall PACKAGENAME
          
Alternatively, the package can be reinstalled from trusted media using the command:
$ sudo rpm -Uvh PACKAGENAME
          
Warning:  This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of packages present on the system. It is not a problem in most cases, but especially systems with a large number of installed packages can be affected.
Rationale:
The hashes of important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_rpm_verify_hashes
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
cui3.3.8, 3.4.1
disaCCI-000366, CCI-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-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3)
nist-csfPR.DS-6, PR.DS-8, PR.IP-1
pcidssReq-11.5
os-srgSRG-OS-000480-GPOS-00227
pcidss411.5.2

Rule   Verify and Correct Ownership with RPM   [ref]

The RPM package management system can check file ownership permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions, which can be found with:
rpm -Va | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }'
run the following command to determine which package owns it:
$ rpm -qf FILENAME
          
Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --setugids PACKAGENAME
          
Warning:  Profiles may require that specific files be owned by root while the default owner defined by the vendor is different. Such files will be reported as a finding and need to be evaluated according to your policy and deployment environment.
Warning:  This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of packages present on the system. It is not a problem in most cases, but especially systems with a large number of installed packages can be affected.
Rationale:
Ownership of binaries and configuration files that is incorrect could allow an unauthorized user to gain privileges that they should not have. The ownership set by the vendor should be maintained. Any deviations from this baseline should be investigated.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_rpm_verify_ownership
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9
cjis5.10.4.1
cobit5APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01
cui3.3.8, 3.4.1
disaCCI-001494, CCI-001496
isa-62443-20094.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 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 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, 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.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cipCIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2
nistCM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3)
nist-csfPR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1
pcidssReq-11.5
os-srgSRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000278-GPOS-00108
pcidss411.5.2
Group   Verify Integrity with AIDE   Group contains 2 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   Install AIDE   [ref]

The aide package can be installed with the following command:
$ sudo yum install aide
Rationale:
The AIDE package must be installed if it is to be available for integrity checking.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_aide_installed
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-002696, CCI-002699, CCI-001744
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
ism1034, 1288, 1341, 1417
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
nistCM-6(a)
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-000445-GPOS-00199
anssiR76, R79
pcidss411.5.2


[[packages]]
name = "aide"
version = "*"

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Ensure aide is installed
  package:
    name: aide
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_aide_installed

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include install_aide

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

Rule   Configure Periodic Execution of AIDE   [ref]

At a minimum, AIDE should be configured to run a weekly scan. To implement a daily execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:
05 4 * * * root /usr/sbin/aide --check
To implement a weekly execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:
05 4 * * 0 root /usr/sbin/aide --check
AIDE can be executed periodically through other means; this is merely one example. The usage of cron's special time codes, such as @daily and @weekly is acceptable.
Rationale:
By default, AIDE does not install itself for periodic execution. Periodically running AIDE is necessary to reveal unexpected changes in installed files.

Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security.

Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_aide_periodic_cron_checking
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-7, SI-7(1), CM-6(a)
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
anssiR76
pcidss411.5.2

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- 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:
  - CJIS-5.10.1.3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_cron_checking
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set cron package name - RedHat
  set_fact:
    cron_pkg_name: cronie
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_os_family == "RedHat" or ansible_os_family == "Suse"
  tags:
  - CJIS-5.10.1.3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_cron_checking
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set cron package name - Debian
  set_fact:
    cron_pkg_name: cron
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_os_family == "Debian"
  tags:
  - CJIS-5.10.1.3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_cron_checking
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Install cron
  package:
    name: '{{ cron_pkg_name }}'
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_cron_checking
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Configure Periodic Execution of AIDE
  cron:
    name: run AIDE check
    minute: 5
    hour: 4
    weekday: 0
    user: root
    job: /usr/sbin/aide --check
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_periodic_cron_checking
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
Group   System Cryptographic Policies   Group contains 2 rules
[ref]   Linux has the capability to centrally configure cryptographic polices. The command update-crypto-policies is used to set the policy applicable for the various cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic policies will be the default policy used by these backends unless the application user configures them otherwise. When the system has been configured to use the centralized cryptographic policies, the administrator is assured that any application that utilizes the supported backends will follow a policy that adheres to the configured profile. Currently the supported backends are:
  • GnuTLS library
  • OpenSSL library
  • NSS library
  • OpenJDK
  • Libkrb5
  • BIND
  • OpenSSH
Applications and languages which rely on any of these backends will follow the system policies as well. Examples are apache httpd, nginx, php, and others.

Rule   Configure System Cryptography Policy   [ref]

To configure the system cryptography policy to use ciphers only from the DEFAULT policy, run the following command:
$ sudo update-crypto-policies --set DEFAULT
         
The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the /etc/crypto-policies/back-ends are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied. Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon.
Warning:  The system needs to be rebooted for these changes to take effect.
Warning:  System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.
Rationale:
Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_configure_crypto_policy
References:
hipaa164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii)
ism1446
nerc-cipCIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1
nistAC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3)
osppFCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), FCS_CKM.1, FCS_CKM.2, FCS_TLSC_EXT.1
os-srgSRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174
pcidss42.2.7

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

- name: Configure System Cryptography Policy
  lineinfile:
    path: /etc/crypto-policies/config
    regexp: ^(?!#)(\S+)$
    line: '{{ var_system_crypto_policy }}'
    create: true
  tags:
  - 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
  - configure_crypto_policy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy

- name: Verify that Crypto Policy is Set (runtime)
  command: /usr/bin/update-crypto-policies --set {{ var_system_crypto_policy }}
  tags:
  - 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
  - configure_crypto_policy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy


var_system_crypto_policy='DEFAULT'


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

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

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

Rule   Configure SSH to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. SSH is supported by crypto policy, but the SSH configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the CRYPTO_POLICY variable is either commented or not set at all in the /etc/sysconfig/sshd.
Rationale:
Overriding the system crypto policy makes the behavior of the SSH service violate expectations, and makes system configuration more fragmented.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_ssh_crypto_policy
References:
disaCCI-001453
hipaa164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii)
nerc-cipCIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1
nistAC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13
osppFCS_SSH_EXT.1, FCS_SSHS_EXT.1, FCS_SSHC_EXT.1
pcidssReq-2.2
os-srgSRG-OS-000250-GPOS-00093
pcidss42.2.7

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Configure SSH to use System Crypto Policy
  lineinfile:
    dest: /etc/sysconfig/sshd
    state: absent
    regexp: (?i)^\s*CRYPTO_POLICY.*$
  tags:
  - 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-13
  - PCI-DSS-Req-2.2
  - PCI-DSSv4-2.2.7
  - configure_ssh_crypto_policy
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required


SSH_CONF="/etc/sysconfig/sshd"

sed -i "/^\s*CRYPTO_POLICY.*$/Id" $SSH_CONF
Group   Sudo   Group contains 4 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   Install sudo Package   [ref]

The sudo package can be installed with the following command:
$ sudo yum install sudo
Rationale:
sudo is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_sudo_installed
References:
ism1382, 1384, 1386
nistCM-6(a)
osppFMT_MOF_EXT.1
os-srgSRG-OS-000324-GPOS-00125
anssiR33
pcidss42.2.6


[[packages]]
name = "sudo"
version = "*"

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Ensure sudo is installed
  package:
    name: sudo
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_sudo_installed

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include install_sudo

class install_sudo {
  package { 'sudo':
    ensure => 'installed',
  }
}

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
References:
pcidssReq-10.2.5
anssiR39
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - 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:
  - 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
References:
pcidssReq-10.2.5
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - 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:
  - 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:
  - 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

Rule   Ensure Users Re-Authenticate for Privilege Escalation - sudo   [ref]

The sudo NOPASSWD and !authenticate option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that NOPASSWD and/or !authenticate do not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/."
Rationale:
Without re-authentication, users may access resources or perform tasks for which they do not have authorization.

When operating systems provide the capability to escalate a functional capability, it is critical that the user re-authenticate.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_require_authentication
References:
cis-csc1, 12, 15, 16, 5
cobit5DSS05.04, DSS05.10, DSS06.03, DSS06.10
disaCCI-002038
isa-62443-20094.3.3.5.1, 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
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
iso27001-2013A.18.1.4, 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-11, CM-6(a)
nist-csfPR.AC-1, PR.AC-7
os-srgSRG-OS-000373-GPOS-00156
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Find /etc/sudoers.d/ files
  ansible.builtin.find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

- name: Remove lines containing NOPASSWD from sudoers files
  ansible.builtin.replace:
    regexp: (^(?!#).*[\s]+NOPASSWD[\s]*\:.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

- name: Find /etc/sudoers.d/ files
  ansible.builtin.find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

- name: Remove lines containing !authenticate from sudoers files
  ansible.builtin.replace:
    regexp: (^(?!#).*[\s]+\!authenticate.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

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

for f in /etc/sudoers /etc/sudoers.d/* ; do
  if [ ! -e "$f" ] ; then
    continue
  fi
  matching_list=$(grep -P '^(?!#).*[\s]+NOPASSWD[\s]*\:.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      # comment out "NOPASSWD" matches to preserve user data
      sed -i "s/^${entry}$/# &/g" $f
    done <<< "$matching_list"

    /usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
  fi
done

for f in /etc/sudoers /etc/sudoers.d/* ; do
  if [ ! -e "$f" ] ; then
    continue
  fi
  matching_list=$(grep -P '^(?!#).*[\s]+\!authenticate.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      # comment out "!authenticate" matches to preserve user data
      sed -i "s/^${entry}$/# &/g" $f
    done <<< "$matching_list"

    /usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
  fi
done
Group   Updating Software   Group contains 2 rules
[ref]   The yum command line tool is used to install and update software packages. The system also provides a graphical software update tool in the System menu, in the Administration submenu, called Software Update.

Alibaba Cloud Linux 3 systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using yum or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.

Rule   Ensure gpgcheck Enabled In Main yum Configuration   [ref]

The gpgcheck option controls whether RPM packages' signatures are always checked prior to installation. To configure yum to check package signatures before installing them, ensure the following line appears in /etc/yum.conf in the [main] section:
gpgcheck=1
Rationale:
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA).
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated
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
anssiR59
pcidss46.3.3

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.10.4.1
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-11(a)
  - NIST-800-53-CM-11(b)
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SA-12
  - NIST-800-53-SA-12(10)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - 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/yum.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when: '"yum" in ansible_facts.packages'
  tags:
  - CJIS-5.10.4.1
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-11(a)
  - NIST-800-53-CM-11(b)
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SA-12
  - NIST-800-53-SA-12(10)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3.3
  - configure_strategy
  - ensure_gpgcheck_globally_activated
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed

Rule   Ensure Software Patches Installed   [ref]



NOTE: U.S. Defense systems are required to be patched within 30 days or sooner as local policy dictates.
Warning:  Alibaba Cloud Linux 3 does not have a corresponding OVAL CVE Feed. Therefore, this will result in a "not checked" result during a scan.
Rationale:
Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_security_patches_up_to_date
References:
cis-csc18, 20, 4
cjis5.10.4.1
cobit5APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02
disaCCI-000366, CCI-001227
isa-62443-20094.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9
iso27001-2013A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3
nistSI-2(5), SI-2(c), CM-6(a)
nist-csfID.RA-1, PR.IP-12
osppFMT_MOF_EXT.1
pcidssReq-6.2
os-srgSRG-OS-000480-GPOS-00227
anssiR61
pcidss46.3.3

Complexity:low
Disruption:high
Reboot:true
Strategy:patch
- name: Security patches are up to date
  package:
    name: '*'
    state: latest
  tags:
  - CJIS-5.10.4.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-2(5)
  - NIST-800-53-SI-2(c)
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3.3
  - high_disruption
  - low_complexity
  - medium_severity
  - patch_strategy
  - reboot_required
  - security_patches_up_to_date
  - skip_ansible_lint
Group   Account and Access Control   Group contains 11 groups and 24 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 Alibaba Cloud Linux 3.
Group   Protect Accounts by Configuring PAM   Group contains 4 groups and 5 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 2 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: password-auth   [ref]

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

On systems with newer versions of authselect, the pam_pwhistory PAM module can be enabled via authselect feature:
authselect enable-feature with-pwhistory
Otherwise, it should be enabled using an authselect custom profile.

Newer systems also have the /etc/security/pwhistory.conf file for setting pam_pwhistory module options. This file should be used whenever available. Otherwise, the pam_pwhistory module options can be set in PAM files.

The value for remember option must be equal or greater than 4
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report.
Warning:  Newer versions of authselect contain an authselect feature to easily and properly enable pam_pwhistory.so module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files. If a custom profile was created and used in the system before this authselect feature was available, the new feature can't be used with this custom profile and the remediation will fail. In this case, the custom profile should be recreated or manually updated.
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_password_auth
References:
cis-csc1, 12, 15, 16, 5
cjis5.6.2.1.1
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.5.8
disaCCI-000200
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
nistIA-5(f), IA-5(1)(e)
nist-csfPR.AC-1, PR.AC-6, PR.AC-7
pcidssReq-8.2.5
os-srgSRG-OS-000077-GPOS-00045
pcidss48.3.7

Rule   Limit Password Reuse: system-auth   [ref]

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

On systems with newer versions of authselect, the pam_pwhistory PAM module can be enabled via authselect feature:
authselect enable-feature with-pwhistory
Otherwise, it should be enabled using an authselect custom profile.

Newer systems also have the /etc/security/pwhistory.conf file for setting pam_pwhistory module options. This file should be used whenever available. Otherwise, the pam_pwhistory module options can be set in PAM files.

The value for remember option must be equal or greater than 4
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report.
Warning:  Newer versions of authselect contain an authselect feature to easily and properly enable pam_pwhistory.so module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files.
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_system_auth
References:
cis-csc1, 12, 15, 16, 5
cjis5.6.2.1.1
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.5.8
disaCCI-000200
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
nistIA-5(f), IA-5(1)(e)
nist-csfPR.AC-1, PR.AC-6, PR.AC-7
pcidssReq-8.2.5
os-srgSRG-OS-000077-GPOS-00045
pcidss48.3.7
Group   Set Password Quality Requirements   Group contains 1 group and 1 rule
[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 with pam_pwquality   Group contains 1 rule
[ref]   The pam_pwquality PAM module can be configured to meet requirements for a variety of policies.

For example, to configure pam_pwquality to require at least one uppercase character, lowercase character, digit, and other (special) character, make sure that pam_pwquality exists in /etc/pam.d/system-auth:
password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth. Next, modify the settings in /etc/security/pwquality.conf to match the following:
difok = 4
minlen = 14
dcredit = -1
ucredit = -1
lcredit = -1
ocredit = -1
maxrepeat = 3
The arguments can be modified to ensure compliance with your organization's security policy. Discussion of each parameter follows.

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

The pam_pwquality module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=12 after pam_pwquality to set minimum password length requirements.
Rationale:
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
References:
cis-csc1, 12, 15, 16, 5
cjis5.6.2.1.1
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
disaCCI-000205
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
ism0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
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)(a), CM-6(a), IA-5(4)
nist-csfPR.AC-1, PR.AC-6, PR.AC-7
osppFMT_SMF_EXT.1
pcidssReq-8.2.3
os-srgSRG-OS-000078-GPOS-00046
anssiR31, R68
pcidss48.3.6

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.1.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_minlen # promote to variable
  set_fact:
    var_password_pam_minlen: !!str 12
  tags:
    - always

- name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure PAM variable
    minlen is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*minlen
    line: minlen = {{ var_password_pam_minlen }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.1.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - accounts_password_pam_minlen
  - 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

var_password_pam_minlen='12'






# 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' <<< "^minlen")

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

# 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 "^minlen\\>" "/etc/security/pwquality.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^minlen\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
    if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Set Password Hashing Algorithm   Group contains 1 rule
[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 Password Hashing Algorithm   [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In "/etc/pam.d/system-auth", 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    sufficient    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
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
anssiR68
pcidss48.3.2

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.2
  - 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/system-auth file
    is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.2
  - 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/system-auth

  - 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 - Check if expected PAM module line
      is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+{{ 'sufficient' | 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: \1sufficient \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    sufficient    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 - Check if the required PAM module
      option is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*\ssha512\b
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_module_sha512_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+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so.*)
      line: \1 sha512
      state: present
    register: result_pam_sha512_add
    when:
    - result_pam_module_sha512_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_sha512_add is defined and result_pam_sha512_add.changed)
       or (result_pam_sha512_edit is defined and result_pam_sha512_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - CJIS-5.6.2.2
  - 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/system-auth" ] ; then
    PAM_FILE_PATH="/etc/pam.d/system-auth"
    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=$(basename "/etc/pam.d/system-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"sufficient"'\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*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
            else
                echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\ssha512\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\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/system-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Protect Accounts by Restricting Password-Based Login   Group contains 4 groups and 18 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 2 rules
Group   Set Password Expiration Parameters   Group contains 3 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 90-day maximum password lifetime restriction by running the following command:
$ sudo chage -M 90
          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
References:
disaCCI-000199
nistIA-5(f), IA-5(1)(d), CM-6(a)
os-srgSRG-OS-000076-GPOS-00044
pcidss48.3.9
Group   Verify Proper Storage and Existence of Password Hashes   Group contains 5 rules
[ref]   By default, password hashes for local accounts are stored in the second field (colon-separated) in /etc/shadow. This file should be readable only by processes running with root credentials, preventing users from casually accessing others' password hashes and attempting to crack them. However, it remains possible to misconfigure the system and store password hashes in world-readable files such as /etc/passwd, or to even store passwords themselves in plaintext on the system. Using system-provided tools for password change/creation should allow administrators to avoid such misconfiguration.

Rule   Verify All Account Password Hashes are Shadowed   [ref]

If any password hashes are stored in /etc/passwd (in the second field, instead of an x or *), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely.
Rationale:
The hashes for all user account passwords should be stored in the file /etc/shadow and never in /etc/passwd, which is readable by all users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_all_shadowed
References:
cis-csc1, 12, 15, 16, 5
cjis5.5.2
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui3.5.10
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
ism1410
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(h), CM-6(a)
nist-csfPR.AC-1, PR.AC-6, PR.AC-7
pcidssReq-8.2.1
pcidss48.3.2

Rule   Ensure all users last password change date is in the past   [ref]

All users should have a password change date in the past.
Warning:  Automatic remediation is not available, in order to avoid any system disruption.
Rationale:
If a user recorded password change date is in the future then they could bypass any set password expiration.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_last_change_is_in_past
References:
pcidss48.3.5

Rule   All GIDs referenced in /etc/passwd must be defined in /etc/group   [ref]

Add a group to the system for each GID referenced without a corresponding group.
Rationale:
If a user is assigned the Group Identifier (GID) of a group not existing on the system, and a group with the Group Identifier (GID) is subsequently created, the user may have unintended rights to any files associated with the group.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_gid_passwd_group_same
References:
cis-csc1, 12, 15, 16, 5
cjis5.5.2
cobit5DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
disaCCI-000764
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
pcidssReq-8.5.a
os-srgSRG-OS-000104-GPOS-00051
pcidss48.2.2

Rule   Prevent Login to Accounts With Empty Password   [ref]

If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the nullok in /etc/pam.d/system-auth and /etc/pam.d/password-auth to prevent logins with empty passwords.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.
Rationale:
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_no_empty_passwords
References:
cis-csc1, 12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2
cobit5APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10
cui3.1.1, 3.1.5
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-62443-20094.3.3.2.2, 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
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 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.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nistIA-5(1)(a), IA-5(c), CM-6(a)
nist-csfPR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5
osppFIA_UAU.1
pcidssReq-8.2.3
os-srgSRG-OS-000480-GPOS-00227
pcidss48.3.1

Rule   Ensure There Are No Accounts With Blank or Null Passwords   [ref]

Check the "/etc/shadow" file for blank passwords with the following command:
$ sudo awk -F: '!$2 {print $1}' /etc/shadow
If the command returns any results, this is a finding. Configure all accounts on the system to have a password or lock the account with the following commands: Perform a password reset:
$ sudo passwd [username]
Lock an account:
$ sudo passwd -l [username]
Warning:  Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.
Rationale:
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_no_empty_passwords_etc_shadow
References:
disaCCI-000366
nistCM-6(b), CM-6.1(iv)
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.2

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Collect users with no password
  command: |
    awk -F: '!$2 {print $1}' /etc/shadow
  register: users_nopasswd
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - PCI-DSSv4-2.2.2
  - high_severity
  - low_complexity
  - low_disruption
  - no_empty_passwords_etc_shadow
  - no_reboot_needed
  - restrict_strategy

- name: Lock users with no password
  command: |
    passwd -l {{ item }}
  with_items: '{{ users_nopasswd.stdout_lines }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - users_nopasswd is not skipped and users_nopasswd.stdout_lines | length > 0
  tags:
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - PCI-DSSv4-2.2.2
  - high_severity
  - low_complexity
  - low_disruption
  - no_empty_passwords_etc_shadow
  - no_reboot_needed
  - restrict_strategy

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

readarray -t users_with_empty_pass < <(sudo awk -F: '!$2 {print $1}' /etc/shadow)

for user_with_empty_pass in "${users_with_empty_pass[@]}"
do
    passwd -l $user_with_empty_pass
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Restrict Root Logins   Group contains 5 rules
[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   Verify Only Root Has UID 0   [ref]

If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed.
If the account is associated with system commands or applications the UID should be changed to one greater than "0" but less than "1000." Otherwise assign a UID greater than "1000" that has not already been assigned.
Rationale:
An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero
References:
cis-csc1, 12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10
cui3.1.1, 3.1.5
disaCCI-000366
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
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 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.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
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, AC-6(5), IA-4(b)
nist-csfPR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5
pcidssReq-8.5
os-srgSRG-OS-000480-GPOS-00227
pcidss48.2.1

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Get all /etc/passwd file entries
  getent:
    database: passwd
    split: ':'
  tags:
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-6(5)
  - NIST-800-53-IA-2
  - NIST-800-53-IA-4(b)
  - PCI-DSS-Req-8.5
  - PCI-DSSv4-8.2.1
  - accounts_no_uid_except_zero
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy

- name: Lock the password of the user accounts other than root with uid 0
  command: passwd -l {{ item.key }}
  loop: '{{ getent_passwd | dict2items | rejectattr(''key'', ''search'', ''root'')
    | list }}'
  when: item.value.1  == '0'
  tags:
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-6(5)
  - NIST-800-53-IA-2
  - NIST-800-53-IA-4(b)
  - PCI-DSS-Req-8.5
  - PCI-DSSv4-8.2.1
  - accounts_no_uid_except_zero
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy

awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs --no-run-if-empty --max-lines=1 passwd -l

Rule   Verify Root Has A Primary GID 0   [ref]

The root user should have a primary group of 0.
Rationale:
To help ensure that root-owned files are not inadvertently exposed to other users.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_accounts_root_gid_zero
References:
pcidssReq-8.1.1
pcidss48.2.1

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, Alibaba Cloud Linux 3'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
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
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:
  - 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

Rule   Ensure that System Accounts Do Not Run a Shell Upon Login   [ref]

Some accounts are not associated with a human user of the system, and exist to perform some administrative functions. Should an attacker be able to log into these accounts, they should not be granted access to a shell.

The login shell for each local account is stored in the last field of each line in /etc/passwd. System accounts are those user accounts with a user ID less than 1000. The user ID is stored in the third field. If any system account other than root has a login shell, disable it with the command:
$ sudo usermod -s /sbin/nologin account
         
Warning:  Do not perform the steps in this section on the root account. Doing so might cause the system to become inaccessible.
Rationale:
Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_shelllogin_for_systemaccounts
References:
cis-csc1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cobit5DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS06.03
disaCCI-000366
isa-62443-20094.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013SR 1.1, 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
ism1491
iso27001-2013A.12.4.1, A.12.4.3, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nistAC-6, CM-6(a), CM-6(b), CM-6.1(iv)
nist-csfDE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6
os-srgSRG-OS-000480-GPOS-00227
pcidss48.2.2

Complexity:low
Disruption:medium
Reboot:false
Strategy:restrict
- name: Ensure that System Accounts Do Not Run a Shell Upon Login - Get All Local
    Users From /etc/passwd
  ansible.builtin.getent:
    database: passwd
    split: ':'
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - PCI-DSSv4-8.2.2
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - no_shelllogin_for_systemaccounts
  - restrict_strategy

- name: Ensure that System Accounts Do Not Run a Shell Upon Login - Create local_users
    Variable From getent_passwd Facts
  ansible.builtin.set_fact:
    local_users: '{{ ansible_facts.getent_passwd | dict2items }}'
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - PCI-DSSv4-8.2.2
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - no_shelllogin_for_systemaccounts
  - restrict_strategy

- name: Ensure that System Accounts Do Not Run a Shell Upon Login -  Disable Login
    Shell for System Accounts
  ansible.builtin.user:
    name: '{{ item.key }}'
    shell: /sbin/nologin
  loop: '{{ local_users }}'
  when:
  - item.key not in ['root']
  - item.value[1]|int < 1000
  - item.value[5] not in ['/sbin/shutdown', '/sbin/halt', '/bin/sync']
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - PCI-DSSv4-8.2.2
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - no_shelllogin_for_systemaccounts
  - restrict_strategy

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

readarray -t systemaccounts < <(awk -F: '($3 < 1000 && $3 != root \
  && $7 != "\/sbin\/shutdown" && $7 != "\/sbin\/halt" && $7 != "\/bin\/sync") \
  { print $1 }' /etc/passwd)

for systemaccount in "${systemaccounts[@]}"; do
    usermod -s /sbin/nologin "$systemaccount"
done

Rule   Ensure All Groups on the System Have Unique Group ID   [ref]

Change the group name or delete groups, so each has a unique id.
Warning:  Automatic remediation of this control is not available due to the unique requirements of each system.
Rationale:
To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_group_unique_id
References:
disaCCI-000764
os-srgSRG-OS-000104-GPOS-00051
pcidss48.2.1

Rule   Ensure All Groups on the System Have Unique Group Names   [ref]

Change the group name or delete groups, so each has a unique name.
Warning:  Automatic remediation of this control is not available due to the unique requirements of each system.
Rationale:
To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_group_unique_name
References:
pcidss48.2.1
Group   Secure Session Configuration Files for Login Accounts   Group contains 1 rule
[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.

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 a file loaded by /etc/profile, e.g. /etc/profile.d/tmout.sh should read as follows:
typeset -xr TMOUT=600
        
or
declare -xr TMOUT=600
        
Using the typeset keyword is preferred for wider compatibility with ksh and other shells.
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
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
anssiR32
pcidss48.6.1

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

- name: Correct any occurrence of TMOUT in /etc/profile
  replace:
    path: /etc/profile
    regexp: ^[^#].*TMOUT=.*
    replace: typeset -xr TMOUT={{ var_accounts_tmout }}
  register: profile_replaced
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - 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
  lineinfile:
    path: /etc/profile.d/tmout.sh
    create: true
    regexp: TMOUT=
    line: typeset -xr TMOUT={{ var_accounts_tmout }}
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - 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='600'


# if 0, no occurence of tmout found, if 1, occurence found
tmout_found=0


for f in /etc/profile /etc/profile.d/*.sh; do

    if grep --silent '^[^#].*TMOUT' $f; then
        sed -i -E "s/^(.*)TMOUT\s*=\s*(\w|\$)*(.*)$/typeset -xr TMOUT=$var_accounts_tmout\3/g" $f
        tmout_found=1
    fi
done

if [ $tmout_found -eq 0 ]; then
        echo -e "\n# Set TMOUT to $var_accounts_tmout per security requirements" >> /etc/profile.d/tmout.sh
        echo "typeset -xr TMOUT=$var_accounts_tmout" >> /etc/profile.d/tmout.sh
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   GRUB2 bootloader configuration   Group contains 1 group and 3 rules
[ref]   During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows for the selection of different kernels - possibly on different partitions or media. The default Alibaba Cloud Linux 3 boot loader for x86 systems is called GRUB2. Options it can pass to the kernel include single-user mode, which provides root access without any authentication, and the ability to disable SELinux. To prevent local users from modifying the boot parameters and endangering security, protect the boot loader configuration with a password and ensure its configuration file's permissions are set properly.
Group   Non-UEFI GRUB2 bootloader configuration   Group contains 3 rules
[ref]   Non-UEFI GRUB2 bootloader configuration

Rule   Verify /boot/grub2/grub.cfg Group Ownership   [ref]

The file /boot/grub2/grub.cfg should be group-owned by the root group to prevent destruction or modification of the file. To properly set the group owner of /boot/grub2/grub.cfg, run the command:
$ sudo chgrp root /boot/grub2/grub.cfg
Rationale:
The root group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_grub2_cfg
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2.2
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
cui3.4.5
disaCCI-000225
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
pcidssReq-7.1
os-srgSRG-OS-000480-GPOS-00227
anssiR29
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    group: '0'
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_grub2_cfg
  - 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 [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chgrp 0 /boot/grub2/grub.cfg

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

Rule   Verify /boot/grub2/grub.cfg User Ownership   [ref]

The file /boot/grub2/grub.cfg should be owned by the root user to prevent destruction or modification of the file. To properly set the owner of /boot/grub2/grub.cfg, run the command:
$ sudo chown root /boot/grub2/grub.cfg 
Rationale:
Only root should be able to modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_grub2_cfg
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2.2
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
cui3.4.5
disaCCI-000225
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
pcidssReq-7.1
os-srgSRG-OS-000480-GPOS-00227
anssiR29
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    owner: '0'
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_grub2_cfg
  - 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 [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chown 0 /boot/grub2/grub.cfg

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

Rule   Verify /boot/grub2/grub.cfg Permissions   [ref]

File permissions for /boot/grub2/grub.cfg should be set to 600. To properly set the permissions of /boot/grub2/grub.cfg, run the command:
$ sudo chmod 600 /boot/grub2/grub.cfg
Rationale:
Proper permissions ensure that only the root user can modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
cui3.4.5
disaCCI-000225
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
anssiR29
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_grub2_cfg
  - 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 [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chmod u-xs,g-xwrs,o-xwrt /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Configure Syslog   Group contains 2 groups and 4 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 Alibaba Cloud Linux 3, 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   Ensure Proper Configuration of Log Files   Group contains 3 rules
[ref]   The file /etc/rsyslog.conf controls where log message are written. These are controlled by lines called rules, which consist of a selector and an action. These rules are often customized depending on the role of the system, the requirements of the environment, and whatever may enable the administrator to most effectively make use of log data. The default rules in Alibaba Cloud Linux 3 are:
*.info;mail.none;authpriv.none;cron.none                /var/log/messages
authpriv.*                                              /var/log/secure
mail.*                                                  -/var/log/maillog
cron.*                                                  /var/log/cron
*.emerg                                                 *
uucp,news.crit                                          /var/log/spooler
local7.*                                                /var/log/boot.log
See the man page rsyslog.conf(5) for more information. Note that the rsyslog daemon can be configured to use a timestamp format that some log processing programs may not understand. If this occurs, edit the file /etc/rsyslog.conf and add or edit the following line:
$ ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat

Rule   Ensure Log Files Are Owned By Appropriate Group   [ref]

The group-owner of all log files written by rsyslog should be root. These log files are determined by the second part of each Rule line in /etc/rsyslog.conf and typically all appear in /var/log. For each log file LOGFILE referenced in /etc/rsyslog.conf, run the following command to inspect the file's group owner:
$ ls -l LOGFILE
        
If the owner is not root, run the following command to correct this:
$ sudo chgrp root LOGFILE
        
Rationale:
The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_rsyslog_files_groupownership
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
disaCCI-001314
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
ism0988, 1405
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-10.5.1, Req-10.5.2
anssiR71
pcidss410.3.2

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Ensure Log Files Are Owned By Appropriate Group - Set rsyslog logfile configuration
    facts
  ansible.builtin.set_fact:
    rsyslog_etc_config: /etc/rsyslog.conf
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Get IncludeConfig directive
  ansible.builtin.shell: |
    set -o pipefail
    grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
  register: rsyslog_old_inc
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Get include files directives
  ansible.builtin.shell: |
    set -o pipefail
    awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
  register: rsyslog_new_inc
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Aggregate rsyslog includes
  ansible.builtin.set_fact:
    include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
      }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - List all config files
  ansible.builtin.find:
    paths: '{{ item | dirname }}'
    patterns: '{{ item | basename }}'
    hidden: false
    follow: true
  loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - include_config_output is defined
  register: rsyslog_config_files
  failed_when: false
  changed_when: false
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files old format
  ansible.builtin.shell: |
    set -o pipefail
    grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
    awk '{print $NF}' | \
    sed -e 's/^-//' || true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_old
  changed_when: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files new format
  ansible.builtin.shell: |
    set -o pipefail
    grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
    grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
    grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
    tr -d "\""|| true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_new
  changed_when: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Sum all log files found
  ansible.builtin.set_fact:
    log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
      | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
      | list | flatten | unique }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group -Setup log files attribute
  ansible.builtin.file:
    path: '{{ item }}'
    group: root
    state: file
  loop: '{{ log_files | list | flatten | unique }}'
  failed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

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

# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
#   (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS

# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
	# If directory, rsyslog will search for config files in recursively.
	# However, files in hidden sub-directories or hidden files will be ignored.
	if [ -d "${ENTRY}" ]
	then
		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
	elif [ -f "${ENTRY}" ]
	then
		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
	else
		echo "Invalid include object: ${ENTRY}"
	fi
done

# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	# From each of these files extract just particular log file path(s), thus:
	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
	# * Ignore empty lines,
	# * Strip quotes and closing brackets from paths.
	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
	# * From the remaining valid rows select only fields constituting a log file path
	# Text file column is understood to represent a log file path if and only if all of the
	# following are met:
	# * it contains at least one slash '/' character,
	# * it is preceded by space
	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
	# Search log file for path(s) only in case it exists!
	if [[ -f "${LOG_FILE}" ]]
	then
		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
		# Since above sed command might return more than one item (delimited by newline), split
		# the particular matches entries into new array specific for this log file
		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
		# items from newly created array for this log file
		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
		# Delete the temporary array
		unset ARRAY_FOR_LOG_FILE
	fi
done

# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done

# Ensure the correct attribute if file exists
FILE_CMD="chgrp"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
	if [ -z "$LOG_FILE_PATH" ]
	then
		continue
	fi
	$FILE_CMD "root" "$LOG_FILE_PATH"
done

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

Rule   Ensure Log Files Are Owned By Appropriate User   [ref]

The owner of all log files written by rsyslog should be root. These log files are determined by the second part of each Rule line in /etc/rsyslog.conf and typically all appear in /var/log. For each log file LOGFILE referenced in /etc/rsyslog.conf, run the following command to inspect the file's owner:
$ ls -l LOGFILE
        
If the owner is not root, run the following command to correct this:
$ sudo chown root LOGFILE
        
Rationale:
The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_rsyslog_files_ownership
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
disaCCI-001314
isa-62443-20094.3.3.7.3
isa-62443-2013SR 2.1, SR 5.2
ism0988, 1405
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-10.5.1, Req-10.5.2
anssiR71
pcidss410.3.2

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Ensure Log Files Are Owned By Appropriate User - Set rsyslog logfile configuration
    facts
  ansible.builtin.set_fact:
    rsyslog_etc_config: /etc/rsyslog.conf
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Get IncludeConfig directive
  ansible.builtin.shell: |
    set -o pipefail
    grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
  register: rsyslog_old_inc
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Get include files directives
  ansible.builtin.shell: |
    set -o pipefail
    awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
  register: rsyslog_new_inc
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Aggregate rsyslog includes
  ansible.builtin.set_fact:
    include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
      }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - List all config files
  ansible.builtin.find:
    paths: '{{ item | dirname }}'
    patterns: '{{ item | basename }}'
    hidden: false
    follow: true
  loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - include_config_output is defined
  register: rsyslog_config_files
  failed_when: false
  changed_when: false
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Extract log files old format
  ansible.builtin.shell: |
    set -o pipefail
    grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
    awk '{print $NF}' | \
    sed -e 's/^-//' || true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_old
  changed_when: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Extract log files new format
  ansible.builtin.shell: |
    set -o pipefail
    grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
    grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
    grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
    tr -d "\""|| true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_new
  changed_when: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Sum all log files found
  ansible.builtin.set_fact:
    log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
      | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
      | list | flatten | unique }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User -Setup log files attribute
  ansible.builtin.file:
    path: '{{ item }}'
    owner: root
    state: file
  loop: '{{ log_files | list | flatten | unique }}'
  failed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

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

# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
#   (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS

# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
	# If directory, rsyslog will search for config files in recursively.
	# However, files in hidden sub-directories or hidden files will be ignored.
	if [ -d "${ENTRY}" ]
	then
		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
	elif [ -f "${ENTRY}" ]
	then
		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
	else
		echo "Invalid include object: ${ENTRY}"
	fi
done

# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	# From each of these files extract just particular log file path(s), thus:
	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
	# * Ignore empty lines,
	# * Strip quotes and closing brackets from paths.
	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
	# * From the remaining valid rows select only fields constituting a log file path
	# Text file column is understood to represent a log file path if and only if all of the
	# following are met:
	# * it contains at least one slash '/' character,
	# * it is preceded by space
	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
	# Search log file for path(s) only in case it exists!
	if [[ -f "${LOG_FILE}" ]]
	then
		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
		# Since above sed command might return more than one item (delimited by newline), split
		# the particular matches entries into new array specific for this log file
		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
		# items from newly created array for this log file
		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
		# Delete the temporary array
		unset ARRAY_FOR_LOG_FILE
	fi
done

# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done

# Ensure the correct attribute if file exists
FILE_CMD="chown"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
	if [ -z "$LOG_FILE_PATH" ]
	then
		continue
	fi
	$FILE_CMD "root" "$LOG_FILE_PATH"
done

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

Rule   Ensure System Log Files Have Correct Permissions   [ref]

The file permissions for all log files written by rsyslog should be set to 640, or more restrictive. These log files are determined by the second part of each Rule line in /etc/rsyslog.conf and typically all appear in /var/log. For each log file LOGFILE referenced in /etc/rsyslog.conf, run the following command to inspect the file's permissions:
$ ls -l LOGFILE
        
If the permissions are not 640 or more restrictive, run the following command to correct this:
$ sudo chmod 640 LOGFILE
        
"
Rationale:
Log files can contain valuable information regarding system configuration. If the system log files are not protected unauthorized users could change the logged data, eliminating their forensic value.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_rsyslog_files_permissions
References:
disaCCI-001314
ism0988, 1405
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)
pcidssReq-10.5.1, Req-10.5.2
anssiR71
pcidss410.3.1

Complexity:low
Disruption:medium
Reboot:false
Strategy:configure
- name: Ensure System Log Files Have Correct Permissions - Set rsyslog logfile configuration
    facts
  ansible.builtin.set_fact:
    rsyslog_etc_config: /etc/rsyslog.conf
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Get IncludeConfig directive
  ansible.builtin.shell: |
    set -o pipefail
    grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
  register: rsyslog_old_inc
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Get include files directives
  ansible.builtin.shell: |
    set -o pipefail
    awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
  register: rsyslog_new_inc
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Aggregate rsyslog includes
  ansible.builtin.set_fact:
    include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
      }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - List all config files
  ansible.builtin.find:
    paths: '{{ item | dirname }}'
    patterns: '{{ item | basename }}'
    hidden: false
    follow: true
  loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - include_config_output is defined
  register: rsyslog_config_files
  failed_when: false
  changed_when: false
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Extract log files old format
  ansible.builtin.shell: |
    set -o pipefail
    grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
    awk '{print $NF}' | \
    sed -e 's/^-//' || true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_old
  changed_when: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Extract log files new format
  ansible.builtin.shell: |
    set -o pipefail
    grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
    grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
    grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
    tr -d "\""|| true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_new
  changed_when: false
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Sum all log files found
  ansible.builtin.set_fact:
    log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
      | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
      | list | flatten | unique }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions -Setup log files attribute
  ansible.builtin.file:
    path: '{{ item }}'
    mode: '0640'
    state: file
  loop: '{{ log_files | list | flatten | unique }}'
  failed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

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

# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
#   (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS

# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
	# If directory, rsyslog will search for config files in recursively.
	# However, files in hidden sub-directories or hidden files will be ignored.
	if [ -d "${ENTRY}" ]
	then
		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
	elif [ -f "${ENTRY}" ]
	then
		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
	else
		echo "Invalid include object: ${ENTRY}"
	fi
done

# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	# From each of these files extract just particular log file path(s), thus:
	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
	# * Ignore empty lines,
	# * Strip quotes and closing brackets from paths.
	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
	# * From the remaining valid rows select only fields constituting a log file path
	# Text file column is understood to represent a log file path if and only if all of the
	# following are met:
	# * it contains at least one slash '/' character,
	# * it is preceded by space
	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
	# Search log file for path(s) only in case it exists!
	if [[ -f "${LOG_FILE}" ]]
	then
		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
		# Since above sed command might return more than one item (delimited by newline), split
		# the particular matches entries into new array specific for this log file
		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
		# items from newly created array for this log file
		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
		# Delete the temporary array
		unset ARRAY_FOR_LOG_FILE
	fi
done

# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done

# Ensure the correct attribute if file exists
FILE_CMD="chmod"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
	if [ -z "$LOG_FILE_PATH" ]
	then
		continue
	fi
	$FILE_CMD "0640" "$LOG_FILE_PATH"
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Ensure All Logs are Rotated by logrotate   Group contains 1 rule
[ref]   Edit the file /etc/logrotate.d/syslog. Find the first line, which should look like this (wrapped for clarity):
/var/log/messages /var/log/secure /var/log/maillog /var/log/spooler \
  /var/log/boot.log /var/log/cron {
Edit this line so that it contains a one-space-separated listing of each log file referenced in /etc/rsyslog.conf.

All logs in use on a system must be rotated regularly, or the log files will consume disk space over time, eventually interfering with system operation. The file /etc/logrotate.d/syslog is the configuration file used by the logrotate program to maintain all log files written by syslog. By default, it rotates logs weekly and stores four archival copies of each log. These settings can be modified by editing /etc/logrotate.conf, but the defaults are sufficient for purposes of this guide.

Note that logrotate is run nightly by the cron job /etc/cron.daily/logrotate. If particularly active logs need to be rotated more often than once a day, some other mechanism must be used.

Rule   Ensure logrotate is Installed   [ref]

logrotate is installed by default. The logrotate package can be installed with the following command:
 $ sudo yum install logrotate
Rationale:
The logrotate package provides the logrotate services.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_logrotate_installed
References:
cis-csc1, 14, 15, 16, 3, 5, 6
cobit5APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01
disaCCI-000366
isa-62443-20094.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9
iso27001-2013A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1
nistCM-6(a)
nist-csfPR.PT-1
pcidssReq-10.7
anssiR71
pcidss410.5.1


[[packages]]
name = "logrotate"
version = "*"

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Ensure logrotate is installed
  package:
    name: logrotate
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - PCI-DSSv4-10.5.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_logrotate_installed

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include install_logrotate

class install_logrotate {
  package { 'logrotate':
    ensure => 'installed',
  }
}
Group   Network Configuration and Firewalls   Group contains 13 groups and 17 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   firewalld   Group contains 1 group and 2 rules
[ref]   The dynamic firewall daemon firewalld provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly.
A graphical configuration tool, firewall-config, is used to configure firewalld, which in turn uses iptables tool to communicate with Netfilter in the kernel which implements packet filtering.
The firewall service provided by firewalld is dynamic rather than static because changes to the configuration can be made at anytime and are immediately implemented. There is no need to save or apply the changes. No unintended disruption of existing network connections occurs as no part of the firewall has to be reloaded.
Group   Inspect and Activate Default firewalld Rules   Group contains 2 rules
[ref]   Firewalls can be used to separate networks into different zones based on the level of trust the user has decided to place on the devices and traffic within that network. NetworkManager informs firewalld to which zone an interface belongs. An interface's assigned zone can be changed by NetworkManager or via the firewall-config tool.
The zone settings in /etc/firewalld/ are a range of preset settings which can be quickly applied to a network interface. These are the zones provided by firewalld sorted according to the default trust level of the zones from untrusted to trusted:
  • drop

    Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.

  • block

    Any incoming network connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6. Only network connections initiated from within the system are possible.

  • public

    For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

  • external

    For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

  • dmz

    For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.

  • work

    For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

  • home

    For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

  • internal

    For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.

  • trusted

    All network connections are accepted.


It is possible to designate one of these zones to be the default zone. When interface connections are added to NetworkManager, they are assigned to the default zone. On installation, the default zone in firewalld is set to be the public zone.
To find out all the settings of a zone, for example the public zone, enter the following command as root:
# firewall-cmd --zone=public --list-all
Example output of this command might look like the following:
# firewall-cmd --zone=public --list-all
public
  interfaces:
  services: mdns dhcpv6-client ssh
  ports:
  forward-ports:
  icmp-blocks: source-quench
To view the network zones currently active, enter the following command as root:
# firewall-cmd --get-service
The following listing displays the result of this command on common Alibaba Cloud Linux 3 system:
# firewall-cmd --get-service
amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
samba samba-client smtp ssh telnet tftp tftp-client transmission-client
vnc-server wbem-https
Finally to view the network zones that will be active after the next firewalld service reload, enter the following command as root:
# firewall-cmd --get-service --permanent

Rule   Install firewalld Package   [ref]

The firewalld package can be installed with the following command:
$ sudo yum install firewalld
Rationale:
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Alibaba Cloud Linux 3 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets)."
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_firewalld_installed
References:
disaCCI-002314
nistCM-6(a)
osppFMT_SMF_EXT.1
os-srgSRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000298-GPOS-00116, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00232
pcidss41.2.1


[[packages]]
name = "firewalld"
version = "*"

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Ensure firewalld is installed
  package:
    name: firewalld
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-1.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_firewalld_installed

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include install_firewalld

class install_firewalld {
  package { 'firewalld':
    ensure => 'installed',
  }
}

Rule   Verify firewalld Enabled   [ref]

The firewalld service can be enabled with the following command:
$ sudo systemctl enable firewalld.service
Rationale:
Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_firewalld_enabled
References:
cis-csc11, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05
cui3.1.3, 3.4.7
disaCCI-000366, CCI-000382, CCI-002314
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
nerc-cipCIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3
nistAC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a)
nist-csfPR.IP-1
osppFMT_SMF_EXT.1
os-srgSRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232
pcidss41.2.1


[customizations.services]
enabled = ["firewalld"]

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.3
  - NIST-800-171-3.4.7
  - NIST-800-53-AC-4
  - NIST-800-53-CA-3(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(21)
  - PCI-DSSv4-1.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_firewalld_enabled

- name: Verify firewalld Enabled - Enable service firewalld
  block:

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

  - name: Verify firewalld Enabled - Enable Service firewalld
    ansible.builtin.systemd:
      name: firewalld
      enabled: true
      state: started
      masked: false
    when:
    - '"firewalld" in ansible_facts.packages'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"firewalld" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.3
  - NIST-800-171-3.4.7
  - NIST-800-53-AC-4
  - NIST-800-53-CA-3(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(21)
  - PCI-DSSv4-1.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_firewalld_enabled

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include enable_firewalld

class enable_firewalld {
  service {'firewalld':
    enable => true,
    ensure => 'running',
  }
}
Group   iptables and ip6tables   Group contains 1 group and 1 rule
[ref]   A host-based firewall called netfilter is included as part of the Linux kernel distributed with the system. It is activated by default. This firewall is controlled by the program iptables, and the entire capability is frequently referred to by this name. An analogous program called ip6tables handles filtering for IPv6.

Unlike TCP Wrappers, which depends on the network server program to support and respect the rules written, netfilter filtering occurs at the kernel level, before a program can even process the data from the network packet. As such, any program on the system is affected by the rules written.

This section provides basic information about strengthening the iptables and ip6tables configurations included with the system. For more complete information that may allow the construction of a sophisticated ruleset tailored to your environment, please consult the references at the end of this section.
Group   Inspect and Activate Default Rules   Group contains 1 rule
[ref]   View the currently-enforced iptables rules by running the command:
$ sudo iptables -nL --line-numbers
The command is analogous for ip6tables.

If the firewall does not appear to be active (i.e., no rules appear), activate it and ensure that it starts at boot by issuing the following commands (and analogously for ip6tables):
$ sudo service iptables restart
The default iptables rules are:
Chain INPUT (policy ACCEPT)
num  target     prot opt source       destination
1    ACCEPT     all  --  0.0.0.0/0    0.0.0.0/0    state RELATED,ESTABLISHED 
2    ACCEPT     icmp --  0.0.0.0/0    0.0.0.0/0
3    ACCEPT     all  --  0.0.0.0/0    0.0.0.0/0
4    ACCEPT     tcp  --  0.0.0.0/0    0.0.0.0/0    state NEW tcp dpt:22 
5    REJECT     all  --  0.0.0.0/0    0.0.0.0/0    reject-with icmp-host-prohibited 

Chain FORWARD (policy ACCEPT)
num  target     prot opt source       destination
1    REJECT     all  --  0.0.0.0/0    0.0.0.0/0    reject-with icmp-host-prohibited 

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source       destination
The ip6tables default rules are essentially the same.

Rule   Set Default ip6tables Policy for Incoming Packets   [ref]

To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in /etc/sysconfig/ip6tables:
:INPUT DROP [0:0]
If changes were required, reload the ip6tables rules:
$ sudo service ip6tables reload
Rationale:
In ip6tables, the default policy is applied only after all the applicable rules in the table are examined for a match. Setting the default policy to DROP implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_set_ip6tables_default_rule
References:
cis-csc11, 14, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
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
nerc-cipCIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3
nistAC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a)
nist-csfPR.IP-1, PR.PT-3
pcidss41.4.1

# Remediation is applicable only in certain platforms
if ( ! ( rpm --quiet -q nftables ) && ! ( rpm --quiet -q ufw ) && rpm --quiet -q iptables ); then

sed -i 's/^:INPUT ACCEPT.*/:INPUT DROP [0:0]/g' /etc/sysconfig/ip6tables

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   IPv6   Group contains 1 group and 1 rule
[ref]   The system includes support for Internet Protocol version 6. A major and often-mentioned improvement over IPv4 is its enormous increase in the number of available addresses. Another important feature is its support for automatic configuration of many network settings.
Group   Configure IPv6 Settings if Necessary   Group contains 1 rule
[ref]   A major feature of IPv6 is the extent to which systems implementing it can automatically configure their networking devices using information from the network. From a security perspective, manually configuring important configuration information is preferable to accepting it from the network in an unauthenticated fashion.

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command:
$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route
References:
cis-csc1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9
cobit5APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui3.1.20
disaCCI-000366
isa-62443-20094.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013SR 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.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nistCM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv)
nist-csfDE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4
pcidssReq-1.4.3
os-srgSRG-OS-000480-GPOS-00227
anssiR13
pcidss41.4.2

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route

- name: Comment out any occurrences of net.ipv6.conf.default.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_source_route
    replace: '#net.ipv6.conf.default.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_default_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route
Group   Kernel Parameters Which Affect Networking   Group contains 2 groups and 9 rules
[ref]   The sysctl utility is used to set parameters which affect the operation of the Linux kernel. Kernel parameters which affect networking and have security implications are described here.
Group   Network Related Kernel Runtime Parameters for Hosts and Routers   Group contains 6 rules
[ref]   Certain kernel parameters should be set for systems which are acting as either hosts or routers to improve the system's ability defend against certain types of IPv4 protocol attacks.

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.rp_filter = 1
Rationale:
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter
References:
cis-csc1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9
cobit5APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui3.1.20
disaCCI-000366, CCI-001551
isa-62443-20094.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nistCM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4
pcidssReq-1.4.3
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.3

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.rp_filter.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter

- name: Comment out any occurrences of net.ipv4.conf.all.rp_filter from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.rp_filter
    replace: '#net.ipv4.conf.all.rp_filter'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_all_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.rp_filter is set
  sysctl:
    name: net.ipv4.conf.all.rp_filter
    value: '{{ sysctl_net_ipv4_conf_all_rp_filter_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter

Rule   Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.secure_redirects = 0
Rationale:
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cobit5APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui3.1.20
disaCCI-001503, CCI-001551
isa-62443-20094.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
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 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nistCM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
pcidssReq-1.4.3
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.3

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.secure_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.secure_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.secure_redirects
    replace: '#net.ipv4.conf.all.secure_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.all.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_all_secure_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis5.10.1.1
cobit5APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui3.1.20
disaCCI-000366, CCI-001551
isa-62443-20094.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
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 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nistCM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
pcidssReq-1.4.3
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.3

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.accept_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.accept_redirects
    replace: '#net.ipv4.conf.default.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_default_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects

Rule   Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_echo_ignore_broadcasts = 1
Rationale:
Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.
Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_echo_ignore_broadcasts
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis5.10.1.1
cobit5APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui3.1.20
disaCCI-000366
isa-62443-20094.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
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 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cipCIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nistCM-7(a), CM-7(b), SC-5
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
pcidssReq-1.4.3
os-srgSRG-OS-000480-GPOS-00227
pcidss41.4.2

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

- name: Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts
    replace: '#net.ipv4.icmp_echo_ignore_broadcasts'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: XCCDF Value sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_echo_ignore_broadcasts is set
  sysctl:
    name: net.ipv4.icmp_echo_ignore_broadcasts
    value: '{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

Rule   Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_ignore_bogus_error_responses = 1
Rationale:
Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06
cui3.1.20
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 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2
nerc-cipCIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nistCM-7(a), CM-7(b), SC-5
nist-csfDE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3
pcidssReq-1.4.3
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.2

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity

- name: Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses
    from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses
    replace: '#net.ipv4.icmp_ignore_bogus_error_responses'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_ignore_bogus_error_responses is set
  sysctl:
    name: net.ipv4.icmp_ignore_bogus_error_responses
    value: '{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity

Rule   Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces   [ref]

To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.tcp_syncookies = 1
Rationale:
A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies
References:
cis-csc1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9
cjis5.10.1.1
cobit5APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui3.1.20
disaCCI-000366, CCI-001095
isa-62443-20094.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nistCM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a)
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4
pcidssReq-1.4.1
os-srgSRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071
anssiR12
pcidss41.4.3

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.tcp_syncookies.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies

- name: Comment out any occurrences of net.ipv4.tcp_syncookies from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.tcp_syncookies
    replace: '#net.ipv4.tcp_syncookies'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies
- name: XCCDF Value sysctl_net_ipv4_tcp_syncookies_value # promote to variable
  set_fact:
    sysctl_net_ipv4_tcp_syncookies_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.tcp_syncookies is set
  sysctl:
    name: net.ipv4.tcp_syncookies
    value: '{{ sysctl_net_ipv4_tcp_syncookies_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies
Group   Network Parameters for Hosts Only   Group contains 3 rules
[ref]   If the system is not going to be used as a router, then setting certain kernel parameters ensure that the host will not perform routing of network traffic.

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.send_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis5.10.1.1
cobit5APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui3.1.20
disaCCI-000366
isa-62443-20094.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
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 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cipCIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nistCM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.5

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.send_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.5
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.send_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.send_redirects
    replace: '#net.ipv4.conf.all.send_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.5
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

- name: Ensure sysctl net.ipv4.conf.all.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.all.send_redirects
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.5
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.send_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis5.10.1.1
cobit5APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui3.1.20
disaCCI-000366
isa-62443-20094.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
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 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cipCIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nistCM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csfDE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.5

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.send_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.5
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.send_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.send_redirects
    replace: '#net.ipv4.conf.default.send_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.5
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

- name: Ensure sysctl net.ipv4.conf.default.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.default.send_redirects
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.5
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

Rule   Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.ip_forward = 0
Warning:  Certain technologies such as virtual machines, containers, etc. rely on IPv4 forwarding to enable and use networking. Disabling IPv4 forwarding would cause those technologies to stop working. Therefore, this rule should not be used in profiles or benchmarks that target usage of IPv4 forwarding.
Rationale:
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_forward
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06
cui3.1.20
disaCCI-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 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2
nerc-cipCIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nistCM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csfDE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4
pcidssReq-1.3.1, Req-1.3.2
os-srgSRG-OS-000480-GPOS-00227
anssiR12
pcidss41.4.3

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.ip_forward.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.3.1
  - PCI-DSS-Req-1.3.2
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_forward

- name: Comment out any occurrences of net.ipv4.ip_forward from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.ip_forward
    replace: '#net.ipv4.ip_forward'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.3.1
  - PCI-DSS-Req-1.3.2
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_forward

- name: Ensure sysctl net.ipv4.ip_forward is set to 0
  sysctl:
    name: net.ipv4.ip_forward
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.3.1
  - PCI-DSS-Req-1.3.2
  - PCI-DSSv4-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_forward
Group   nftables   Group contains 1 rule
[ref]   If firewalld or iptables are being used in your environment, please follow the guidance in their respective section and pass-over the guidance in this section.

nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables. The biggest change with the successor nftables is its simplicity. With iptables, we have to configure every single rule and use the syntax which can be compared with normal commands. With nftables, the simpler syntax, much like BPF (Berkely Packet Filter) means shorter lines and less repetition. Support for nftables should also be compiled into the kernel, together with the related nftables modules.

It is available in Linux kernels >= 3.13. Please ensure that your kernel supports nftables before choosing this option.

Rule   Verify nftables Service is Disabled   [ref]

nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables. The nftables service can be disabled with the following command:
systemctl disable nftables
Rationale:
Running both firewalld and nftables may lead to conflict. nftables is actually one of the backends for firewalld management tools.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_nftables_disabled
References:
pcidss41.2.1


[customizations.services]
masked = ["nftables"]

Complexity:low
Disruption:low
Reboot:false
Strategy:disable
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - PCI-DSSv4-1.2.1
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

- name: Verify nftables Service is Disabled - Collect systemd Services Present in
    the System
  ansible.builtin.command: systemctl -q list-unit-files --type service
  register: service_exists
  changed_when: false
  failed_when: service_exists.rc not in [0, 1]
  check_mode: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "firewalld" in ansible_facts.packages and "nftables" in ansible_facts.packages
    )
  tags:
  - PCI-DSSv4-1.2.1
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

- name: Verify nftables Service is Disabled - Ensure nftables.service is Masked
  ansible.builtin.systemd:
    name: nftables.service
    state: stopped
    enabled: false
    masked: true
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "firewalld" in ansible_facts.packages and "nftables" in ansible_facts.packages
    )
  - service_exists.stdout_lines is search("nftables.service", multiline=True)
  tags:
  - PCI-DSSv4-1.2.1
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

- name: Unit Socket Exists - nftables.socket
  ansible.builtin.command: systemctl -q list-unit-files nftables.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "firewalld" in ansible_facts.packages and "nftables" in ansible_facts.packages
    )
  tags:
  - PCI-DSSv4-1.2.1
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

- name: Verify nftables Service is Disabled - Disable Socket nftables
  ansible.builtin.systemd:
    name: nftables.socket
    enabled: false
    state: stopped
    masked: true
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "firewalld" in ansible_facts.packages and "nftables" in ansible_facts.packages
    )
  - socket_file_exists.stdout_lines is search("nftables.socket", multiline=True)
  tags:
  - PCI-DSSv4-1.2.1
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include disable_nftables

class disable_nftables {
  service {'nftables':
    enable => false,
    ensure => 'stopped',
  }
}
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
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
pcidss41.4.2

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
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
pcidss41.4.2
Group   Wireless Networking   Group contains 1 group and 1 rule
[ref]   Wireless networking, such as 802.11 (WiFi) and Bluetooth, can present a security risk to sensitive or classified systems and networks. Wireless networking hardware is much more likely to be included in laptop or portable systems than in desktops or servers.

Removal of hardware provides the greatest assurance that the wireless capability remains disabled. Acquisition policies often include provisions to prevent the purchase of equipment that will be used in sensitive spaces and includes wireless capabilities. If it is impractical to remove the wireless hardware, and policy permits the device to enter sensitive spaces as long as wireless is disabled, efforts should instead focus on disabling wireless capability via software.
Group   Disable Wireless Through Software Configuration   Group contains 1 rule
[ref]   If it is impossible to remove the wireless hardware from the device in question, disable as much of it as possible through software. The following methods can disable software support for wireless networking, but note that these methods do not prevent malicious software or careless users from re-activating the devices.

Rule   Deactivate Wireless Network Interfaces   [ref]

Deactivating wireless network interfaces should prevent normal usage of the wireless capability.

Configure the system to disable all wireless network interfaces with the following command:
$ sudo nmcli radio all off
Rationale:
The use of wireless networking can introduce many different attack vectors into the organization's network. Common attack vectors such as malicious association and ad hoc networks will allow an attacker to spoof a wireless access point (AP), allowing validated systems to connect to the malicious AP and enabling the attacker to monitor and record network traffic. These malicious APs can also serve to create a man-in-the-middle attack or be used to create a denial of service to valid network resources.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_wireless_disable_interfaces
References:
cis-csc11, 12, 14, 15, 3, 8, 9
cobit5APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06
cui3.1.16
disaCCI-000085, CCI-002418, CCI-002421, CCI-001443, CCI-001444
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 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
ism1315, 1319
iso27001-2013A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nistAC-18(a), AC-18(3), CM-7(a), CM-7(b), CM-6(a), MP-7
nist-csfPR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4
pcidssReq-1.3.3
os-srgSRG-OS-000299-GPOS-00117, SRG-OS-000300-GPOS-00118, SRG-OS-000424-GPOS-00188, SRG-OS-000481-GPOS-000481
pcidss41.3.3

Complexity:low
Disruption:medium
Reboot:false
Strategy:unknown
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.16
  - NIST-800-53-AC-18(3)
  - NIST-800-53-AC-18(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - PCI-DSS-Req-1.3.3
  - PCI-DSSv4-1.3.3
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy
  - wireless_disable_interfaces

- name: Service facts
  ansible.builtin.service_facts: null
  tags:
  - NIST-800-171-3.1.16
  - NIST-800-53-AC-18(3)
  - NIST-800-53-AC-18(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - PCI-DSS-Req-1.3.3
  - PCI-DSSv4-1.3.3
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy
  - wireless_disable_interfaces

- name: Ensure NetworkManager is installed
  ansible.builtin.package:
    name: '{{ item }}'
    state: present
  with_items:
  - NetworkManager
  tags:
  - NIST-800-171-3.1.16
  - NIST-800-53-AC-18(3)
  - NIST-800-53-AC-18(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - PCI-DSS-Req-1.3.3
  - PCI-DSSv4-1.3.3
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy
  - wireless_disable_interfaces

- name: NetworkManager Deactivate Wireless Network Interfaces
  command: nmcli radio wifi off
  when:
  - '''NetworkManager'' in ansible_facts.packages'
  - ansible_facts.services['NetworkManager.service'].state == 'running'
  tags:
  - NIST-800-171-3.1.16
  - NIST-800-53-AC-18(3)
  - NIST-800-53-AC-18(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - PCI-DSS-Req-1.3.3
  - PCI-DSSv4-1.3.3
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy
  - wireless_disable_interfaces


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

if command -v nmcli >/dev/null 2>&1 && systemctl is-active NetworkManager >/dev/null 2>&1; then
    nmcli radio all off
fi

if command -v wicked >/dev/null 2>&1 && systemctl is-active wickedd >/dev/null 2>&1; then
  if [ -n "$(find /sys/class/net/*/ -type d -name wireless)" ]; then
    interfaces=$(find /sys/class/net/*/wireless -type d -name wireless | xargs -0 dirname | xargs basename)
    for iface in $interfaces; do
      wicked ifdown $iface
      sed -i 's/STARTMODE=.*/STARTMODE=off/' /etc/sysconfig/network/ifcfg-$iface
    done
  fi
fi
Group   File Permissions and Masks   Group contains 6 groups and 27 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 Alibaba Cloud Linux 3 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 1 group and 21 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 18 rules

Rule   Verify Group Who Owns Backup group File   [ref]

To properly set the group owner of /etc/group-, run the command:
$ sudo chgrp root /etc/group-
Rationale:
The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_group
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

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

- name: Ensure group owner 0 on /etc/group-
  file:
    path: /etc/group-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chgrp 0 /etc/group-

Rule   Verify Group Who Owns Backup passwd File   [ref]

To properly set the group owner of /etc/passwd-, run the command:
$ sudo chgrp root /etc/passwd-
Rationale:
The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_passwd
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

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

- name: Ensure group owner 0 on /etc/passwd-
  file:
    path: /etc/passwd-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chgrp 0 /etc/passwd-

Rule   Verify User Who Owns Backup shadow File   [ref]

To properly set the group owner of /etc/shadow-, run the command:
$ sudo chgrp root /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_groupowner_backup_etc_shadow
References:
pcidssReq-8.7
os-srgSRG-OS-000480-GPOS-00227
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:
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/shadow-
  file:
    path: /etc/shadow-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chgrp 0 /etc/shadow-

Rule   Verify Group Who Owns group File   [ref]

To properly set the group owner of /etc/group, run the command:
$ sudo chgrp root /etc/group
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_group
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2.2
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - 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_groupowner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/group
  file:
    path: /etc/group
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_groupowner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chgrp 0 /etc/group

Rule   Verify Group Who Owns passwd File   [ref]

To properly set the group owner of /etc/passwd, run the command:
$ sudo chgrp root /etc/passwd
Rationale:
The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2.2
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - 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_groupowner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_groupowner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chgrp 0 /etc/passwd

Rule   Verify Group Who Owns shadow File   [ref]

To properly set the group owner of /etc/shadow, run the command:
$ sudo chgrp root /etc/shadow
Rationale:
The /etc/shadow file stores password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cjis5.5.2.2
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
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:
  - 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_groupowner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/shadow
  file:
    path: /etc/shadow
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_groupowner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chgrp 0 /etc/shadow

Rule   Verify User Who Owns Backup group File   [ref]

To properly set the owner of /etc/group-, run the command:
$ sudo chown root /etc/group- 
Rationale:
The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_backup_etc_group
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

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

- name: Ensure owner 0 on /etc/group-
  file:
    path: /etc/group-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chown 0 /etc/group-

Rule   Verify User Who Owns Backup passwd File   [ref]

To properly set the owner of /etc/passwd-, run the command:
$ sudo chown root /etc/passwd- 
Rationale:
The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_backup_etc_passwd
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

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

- name: Ensure owner 0 on /etc/passwd-
  file:
    path: /etc/passwd-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chown 0 /etc/passwd-

Rule   Verify Group Who Owns Backup shadow File   [ref]

To properly set the owner of /etc/shadow-, run the command:
$ sudo chown root /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_owner_backup_etc_shadow
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
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:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/shadow-
  file:
    path: /etc/shadow-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chown 0 /etc/shadow-

Rule   Verify User Who Owns group File   [ref]

To properly set the owner of /etc/group, run the command:
$ sudo chown root /etc/group 
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_group
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
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - 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_owner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/group
  file:
    path: /etc/group
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_owner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chown 0 /etc/group

Rule   Verify User Who Owns passwd File   [ref]

To properly set the owner of /etc/passwd, run the command:
$ sudo chown root /etc/passwd 
Rationale:
The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_passwd
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
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - 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_owner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_owner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chown 0 /etc/passwd

Rule   Verify User Who Owns shadow File   [ref]

To properly set the owner of /etc/shadow, run the command:
$ sudo chown root /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_owner_etc_shadow
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
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:
  - 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_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/shadow
  file:
    path: /etc/shadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
chown 0 /etc/shadow

Rule   Verify Permissions on Backup group File   [ref]

To properly set the permissions of /etc/group-, run the command:
$ sudo chmod 0644 /etc/group-
Rationale:
The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_group
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

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

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

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





chmod u-xs,g-xws,o-xwt /etc/group-

Rule   Verify Permissions on Backup passwd File   [ref]

To properly set the permissions of /etc/passwd-, run the command:
$ sudo chmod 0644 /etc/passwd-
Rationale:
The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_passwd
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

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

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

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





chmod u-xs,g-xws,o-xwt /etc/passwd-

Rule   Verify Permissions on Backup shadow File   [ref]

To properly set the permissions of /etc/shadow-, run the command:
$ sudo chmod 0000 /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
References:
disaCCI-002223
nistAC-6 (1)
pcidssReq-8.7.c
os-srgSRG-OS-000480-GPOS-00227
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:
  - 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-xwrs,g-xwrs,o-xwrt on /etc/shadow-
  file:
    path: /etc/shadow-
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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-xwrs,g-xwrs,o-xwrt /etc/shadow-

Rule   Verify Permissions on group File   [ref]

To properly set the permissions of /etc/group, run the command:
$ sudo chmod 0644 /etc/group
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_group
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
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - 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_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
  file:
    path: /etc/group
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

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





chmod u-xs,g-xws,o-xwt /etc/group

Rule   Verify Permissions on passwd File   [ref]

To properly set the permissions of /etc/passwd, run the command:
$ sudo chmod 0644 /etc/passwd
Rationale:
If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_passwd
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
anssiR50
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - 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_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
  file:
    path: /etc/passwd
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

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





chmod u-xs,g-xws,o-xwt /etc/passwd

Rule   Verify Permissions on shadow File   [ref]

To properly set the permissions of /etc/shadow, run the command:
$ sudo chmod 0000 /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
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
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:
  - 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-xwrs,g-xwrs,o-xwrt on /etc/shadow
  file:
    path: /etc/shadow
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - 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-xwrs,g-xwrs,o-xwrt /etc/shadow

Rule   Verify that All World-Writable Directories Have Sticky Bits Set   [ref]

When the so-called 'sticky bit' is set on a directory, only the owner of a given file may remove that file from the directory. Without the sticky bit, any user with write access to a directory may remove any file in the directory. Setting the sticky bit prevents users from removing each other's files. In cases where there is no reason for a directory to be world-writable, a better solution is to remove that permission rather than to set the sticky bit. However, if a directory is used by a particular application, consult that application's documentation instead of blindly changing modes.
To set the sticky bit on a world-writable directory DIR, run the following command:
$ sudo chmod +t DIR
        
Warning:  This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of directories present on the system. It is not a problem in most cases, but especially systems with a large number of directories can be affected. See https://access.redhat.com/articles/6999111.
Rationale:
Failing to set the sticky bit on public directories allows unauthorized users to delete files in the directory structure.

The only authorized public directories are those temporary directories supplied with the system, or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system, by users for temporary file storage (such as /tmp), and for directories requiring global read/write access.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_dir_perms_world_writable_sticky_bits
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
disaCCI-001090
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
os-srgSRG-OS-000138-GPOS-00069
anssiR54
pcidss42.2.6

Rule   Ensure No World-Writable Files Exist   [ref]

It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account. Finally, this applies to real files and not virtual files that are a part of pseudo file systems such as sysfs or procfs.
Warning:  This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of files present on the system. It is not a problem in most cases, but especially systems with a large number of files can be affected. See https://access.redhat.com/articles/6999111.
Rationale:
Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_unauthorized_world_writable
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
nistCM-6(a), AC-6(1)
nist-csfPR.AC-4, PR.DS-5
anssiR54
pcidss42.2.6

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

FILTER_NODEV=$(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
PARTITIONS=$(findmnt -n -l -k -it $FILTER_NODEV | awk '{ print $1 }')
for PARTITION in $PARTITIONS; do
  find "${PARTITION}" -xdev -type f -perm -002 -exec chmod o-w {} \; 2>/dev/null
done

# Ensure /tmp is also fixed whem tmpfs is used.
if grep "^tmpfs /tmp" /proc/mounts; then
  find /tmp -xdev -type f -perm -002 -exec chmod o-w {} \; 2>/dev/null
fi

Rule   Ensure All Files Are Owned by a Group   [ref]

If any file is not group-owned by a group present in /etc/group, the cause of the lack of group-ownership must be investigated. Following this, those files should be deleted or assigned to an appropriate group. Locate the mount points related to local devices by the following command:
$ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
For all mount points listed by the previous command, it is necessary to search for files which do not belong to a valid group using the following command:
$ sudo find MOUNTPOINT -xdev -nogroup 2>/dev/null
Warning:  This rule only considers local groups as valid groups. If you have your groups defined outside /etc/group, the rule won't consider those.
Warning:  This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of files present on the system. It is not a problem in most cases, but especially systems with a large number of files can be affected. See https://access.redhat.com/articles/6999111.
Rationale:
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account, or other similar cases. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_ungroupowned
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10
disaCCI-000366, CCI-002165
isa-62443-20094.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
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 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.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nistCM-6(a), AC-6(1)
nist-csfPR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3
os-srgSRG-OS-000480-GPOS-00227
anssiR53
pcidss42.2.6
Group   Restrict Dynamic Mounting and Unmounting of Filesystems   Group contains 1 rule
[ref]   Linux includes a number of facilities for the automated addition and removal of filesystems on a running system. These facilities may be necessary in many environments, but this capability also carries some risk -- whether direct risk from allowing users to introduce arbitrary filesystems, or risk that software flaws in the automated mount facility itself could allow an attacker to compromise the system.

This command can be used to list the types of filesystems that are available to the currently executing kernel:
$ find /lib/modules/`uname -r`/kernel/fs -type f -name '*.ko'
If these filesystems are not required then they can be explicitly disabled in a configuratio file in /etc/modprobe.d.

Rule   Disable 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
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
pcidss43.4.2
Group   Restrict Programs from Dangerous Execution Patterns   Group contains 2 groups and 5 rules
[ref]   The recommendations in this section are designed to ensure that the system's features to protect against potentially dangerous program execution are activated. These protections are applied at the system initialization or kernel level, and defend against certain types of badly-configured or compromised programs.
Group   Disable Core Dumps   Group contains 4 rules
[ref]   A core dump file is the memory image of an executable program when it was terminated by the operating system due to errant behavior. In most cases, only software developers legitimately need to access these files. The core dump files may also contain sensitive information, or unnecessarily occupy large amounts of disk space.

Once a hard limit is set in /etc/security/limits.conf, or to a file within the /etc/security/limits.d/ directory, a user cannot increase that limit within his or her own session. If access to core dumps is required, consider restricting them to only certain users or groups. See the limits.conf man page for more information.

The core dumps of setuid programs are further protected. The sysctl variable fs.suid_dumpable controls whether the kernel allows core dumps from these programs at all. The default value of 0 is recommended.

Rule   Disable core dump backtraces   [ref]

The ProcessSizeMax option in [Coredump] section of /etc/systemd/coredump.conf specifies the maximum size in bytes of a core which will be processed. Core dumps exceeding this size may be stored, but the backtrace will not be generated.
Warning:  If the /etc/systemd/coredump.conf file does not already contain the [Coredump] section, the value will not be configured correctly.
Rationale:
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended, however there may be overriding operational requirements to enable advanced debuging. Permitting temporary enablement of core dumps during such situations should be reviewed through local needs and policy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_coredump_disable_backtraces
References:
disaCCI-000366
nistCM-6
osppFMT_SMF_EXT.1
pcidssReq-3.2
os-srgSRG-OS-000480-GPOS-00227
pcidss43.3.1.1

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6
  - PCI-DSS-Req-3.2
  - PCI-DSSv4-3.3.1.1
  - coredump_disable_backtraces
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Disable core dump backtraces
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/systemd/coredump.conf
      create: false
      regexp: ^\s*ProcessSizeMax\s*=\s*
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/systemd/coredump.conf
    lineinfile:
      path: /etc/systemd/coredump.conf
      create: false
      regexp: ^\s*ProcessSizeMax\s*=\s*
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/systemd/coredump.conf
    lineinfile:
      path: /etc/systemd/coredump.conf
      create: false
      regexp: ^\s*ProcessSizeMax\s*=\s*
      line: ProcessSizeMax=0
      state: present
  when: '"systemd" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6
  - PCI-DSS-Req-3.2
  - PCI-DSSv4-3.3.1.1
  - coredump_disable_backtraces
  - 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 systemd; then

if [ -e "/etc/systemd/coredump.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*ProcessSizeMax\s*=\s*/Id" "/etc/systemd/coredump.conf"
else
    touch "/etc/systemd/coredump.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/coredump.conf"

cp "/etc/systemd/coredump.conf" "/etc/systemd/coredump.conf.bak"
# Insert at the end of the file
printf '%s\n' "ProcessSizeMax=0" >> "/etc/systemd/coredump.conf"
# Clean up after ourselves.
rm "/etc/systemd/coredump.conf.bak"

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

Rule   Disable storing core dump   [ref]

The Storage option in [Coredump] sectionof /etc/systemd/coredump.conf can be set to none to disable storing core dumps permanently.
Warning:  If the /etc/systemd/coredump.conf file does not already contain the [Coredump] section, the value will not be configured correctly.
Rationale:
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended, however there may be overriding operational requirements to enable advanced debuging. Permitting temporary enablement of core dumps during such situations should be reviewed through local needs and policy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_coredump_disable_storage
References:
disaCCI-000366
nistCM-6
osppFMT_SMF_EXT.1
pcidssReq-3.2
os-srgSRG-OS-000480-GPOS-00227
pcidss43.3.1.1

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6
  - PCI-DSS-Req-3.2
  - PCI-DSSv4-3.3.1.1
  - coredump_disable_storage
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Disable storing core dump
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/systemd/coredump.conf
      create: false
      regexp: ^\s*Storage\s*=\s*
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/systemd/coredump.conf
    lineinfile:
      path: /etc/systemd/coredump.conf
      create: false
      regexp: ^\s*Storage\s*=\s*
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/systemd/coredump.conf
    lineinfile:
      path: /etc/systemd/coredump.conf
      create: false
      regexp: ^\s*Storage\s*=\s*
      line: Storage=none
      state: present
  when: '"systemd" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6
  - PCI-DSS-Req-3.2
  - PCI-DSSv4-3.3.1.1
  - coredump_disable_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 rpm --quiet -q systemd; then

if [ -e "/etc/systemd/coredump.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*Storage\s*=\s*/Id" "/etc/systemd/coredump.conf"
else
    touch "/etc/systemd/coredump.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/coredump.conf"

cp "/etc/systemd/coredump.conf" "/etc/systemd/coredump.conf.bak"
# Insert at the end of the file
printf '%s\n' "Storage=none" >> "/etc/systemd/coredump.conf"
# Clean up after ourselves.
rm "/etc/systemd/coredump.conf.bak"

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

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
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
pcidss43.3.1.1

Complexity:low
Disruption:low
Reboot:false
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - 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:
  - 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

Rule   Disable Core Dumps for SUID programs   [ref]

To set the runtime status of the fs.suid_dumpable kernel parameter, run the following command:
$ sudo sysctl -w fs.suid_dumpable=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
fs.suid_dumpable = 0
Rationale:
The core dump of a setuid program is more likely to contain sensitive data, as the program itself runs with greater privileges than the user who initiated execution of the program. Disabling the ability for any setuid program to write a core file decreases the risk of unauthorized access of such data.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_fs_suid_dumpable
References:
hipaa164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
nistSI-11(a), SI-11(b)
anssiR14
pcidss43.3.1.1

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*fs.suid_dumpable.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: Comment out any occurrences of fs.suid_dumpable from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*fs.suid_dumpable
    replace: '#fs.suid_dumpable'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: Ensure sysctl fs.suid_dumpable is set to 0
  sysctl:
    name: fs.suid_dumpable
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable
Group   Enable ExecShield   Group contains 1 rule
[ref]   ExecShield describes kernel features that provide protection against exploitation of memory corruption errors such as buffer overflows. These features include random placement of the stack and other memory regions, prevention of execution in memory that should only hold data, and special handling of text buffers. These protections are enabled by default on 32-bit systems and controlled through sysctl variables kernel.exec-shield and kernel.randomize_va_space. On the latest 64-bit systems, kernel.exec-shield cannot be enabled or disabled with sysctl.

Rule   Enable Randomized Layout of Virtual Address Space   [ref]

To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command:
$ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.randomize_va_space = 2
Rationale:
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space
References:
cui3.1.7
disaCCI-000366, CCI-002824
hipaa164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
nerc-cipCIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4
nistSC-30, SC-30(2), CM-6(a)
pcidssReq-2.2.1
os-srgSRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227
app-srg-ctrSRG-APP-000450-CTR-001105
anssiR9
pcidss43.3.1.1

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*kernel.randomize_va_space.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Comment out any occurrences of kernel.randomize_va_space from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.randomize_va_space
    replace: '#kernel.randomize_va_space'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Ensure sysctl kernel.randomize_va_space is set to 2
  sysctl:
    name: kernel.randomize_va_space
    value: '2'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space
Group   SELinux   Group contains 5 rules
[ref]   SELinux is a feature of the Linux kernel which can be used to guard against misconfigured or compromised programs. SELinux enforces the idea that programs should be limited in what files they can access and what actions they can take.

The default SELinux policy, as configured on Alibaba Cloud Linux 3, has been sufficiently developed and debugged that it should be usable on almost any system with minimal configuration and a small amount of system administrator training. This policy prevents system services - including most of the common network-visible services such as mail servers, FTP servers, and DNS servers - from accessing files which those services have no valid reason to access. This action alone prevents a huge amount of possible damage from network attacks against services, from trojaned software, and so forth.

This guide recommends that SELinux be enabled using the default (targeted) policy on every Alibaba Cloud Linux 3 system, unless that system has unusual requirements which make a stronger policy appropriate.

Rule   Install libselinux Package   [ref]

The libselinux package can be installed with the following command:
$ sudo yum install libselinux
Rationale:
Security-enhanced Linux is a feature of the Linux kernel and a number of utilities with enhanced security functionality designed to add mandatory access controls to Linux. The libselinux package contains the core library of the Security-enhanced Linux system.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_libselinux_installed
References:
pcidss41.2.6


[[packages]]
name = "libselinux"
version = "*"

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Ensure libselinux is installed
  package:
    name: libselinux
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-1.2.6
  - enable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_libselinux_installed

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include install_libselinux

class install_libselinux {
  package { 'libselinux':
    ensure => 'installed',
  }
}

Rule   Ensure SELinux Not Disabled in /etc/default/grub   [ref]

SELinux can be disabled at boot time by an argument in /etc/default/grub. Remove any instances of selinux=0 from the kernel arguments in that file to prevent SELinux from being disabled at boot.
Rationale:
Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_enable_selinux
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01
cui3.1.2, 3.7.2
disaCCI-000022, CCI-000032
hipaa164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-20094.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
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.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
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
nistAC-3, AC-3(3)(a)
nist-csfDE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4
pcidss41.2.6

Rule   Ensure No Daemons are Unconfined by SELinux   [ref]

Daemons for which the SELinux policy does not contain rules will inherit the context of the parent process. Because daemons are launched during startup and descend from the init process, they inherit the unconfined_service_t context.

To check for unconfined daemons, run the following command:
$ sudo ps -eZ | grep "unconfined_service_t"
It should produce no output in a well-configured system.
Warning:  Automatic remediation of this control is not available. Remediation can be achieved by amending SELinux policy or stopping the unconfined daemons as outlined above.
Rationale:
Daemons which run with the unconfined_service_t context may cause AVC denials, or allow privileges that the daemon does not require.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_selinux_confinement_of_daemons
References:
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9
cobit5APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, MEA02.01
cui3.1.2, 3.1.5, 3.7.2
hipaa164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-20094.3.3.3.9, 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 5.2, SR 7.6
iso27001-2013A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, 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.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, 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-7(a), CM-7(b), CM-6(a), AC-3(3)(a), AC-6
nist-csfPR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, PR.PT-3
pcidss41.2.6

Rule   Configure SELinux Policy   [ref]

The SELinux targeted policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in /etc/selinux/config:
SELINUXTYPE=targeted
       
Other policies, such as mls, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.
Rationale:
Setting the SELinux policy to targeted or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services.

Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in permissive mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to targeted.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_selinux_policytype
References:
bsiAPP.4.4.A4
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01
cui3.1.2, 3.7.2
disaCCI-002165, CCI-002696
hipaa164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-20094.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
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.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, 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, CIP-007-3 R6.5
nistAC-3, AC-3(3)(a), AU-9, SC-7(21)
nist-csfDE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4
os-srgSRG-OS-000445-GPOS-00199
app-srg-ctrSRG-APP-000233-CTR-000585
anssiR46, R64
pcidss41.2.6

Rule   Ensure SELinux State is Enforcing   [ref]

The SELinux state should be set to enforcing at system boot time. In the file /etc/selinux/config, add or correct the following line to configure the system to boot into enforcing mode:
SELINUX=enforcing
       
Rationale:
Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_selinux_state
References:
bsiAPP.4.4.A4
cis-csc1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01
cui3.1.2, 3.7.2
disaCCI-001084, CCI-002165, CCI-002696
hipaa164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-20094.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
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.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cipCIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, 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, CIP-007-3 R6.5
nistAC-3, AC-3(3)(a), AU-9, SC-7(21)
nist-csfDE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4
os-srgSRG-OS-000445-GPOS-00199, SRG-OS-000134-GPOS-00068
anssiR37, R79
pcidss41.2.6
Group   Services   Group contains 16 groups and 55 rules
[ref]   The best protection against vulnerable software is running less software. This section describes how to review the software which Alibaba Cloud Linux 3 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Alibaba Cloud Linux 3 system and provides guidance about which ones can be safely disabled.

Alibaba Cloud Linux 3 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Alibaba Cloud Linux 3 systems, it is highly recommended to select the minimal packages and then build up the system from there.
Group   Avahi Server   Group contains 1 group and 1 rule
[ref]   The Avahi daemon implements the DNS Service Discovery and Multicast DNS protocols, which provide service and host discovery on a network. It allows a system to automatically identify resources on the network, such as printers or web servers. This capability is also known as mDNSresponder and is a major part of Zeroconf networking.
Group   Disable Avahi Server if Possible   Group contains 1 rule
[ref]   Because the Avahi daemon service keeps an open network port, it is subject to network attacks. Disabling it can reduce the system's vulnerability to such attacks.

Rule   Disable Avahi Server Software   [ref]

The avahi-daemon service can be disabled with the following command:
$ sudo systemctl mask --now avahi-daemon.service
Rationale:
Because the Avahi daemon service keeps an open network port, it is subject to network attacks. Its functionality is convenient but is only appropriate if the local network can be trusted.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_avahi-daemon_disabled
References:
cis-csc11, 14, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
disaCCI-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
pcidss42.2.4


[customizations.services]
masked = ["avahi-daemon"]

Complexity:low
Disruption:low
Reboot:false
Strategy:disable
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_avahi-daemon_disabled

- name: Disable Avahi Server Software - Collect systemd Services Present in the System
  ansible.builtin.command: systemctl -q list-unit-files --type service
  register: service_exists
  changed_when: false
  failed_when: service_exists.rc not in [0, 1]
  check_mode: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "avahi" in ansible_facts.packages )
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_avahi-daemon_disabled

- name: Disable Avahi Server Software - Ensure avahi-daemon.service is Masked
  ansible.builtin.systemd:
    name: avahi-daemon.service
    state: stopped
    enabled: false
    masked: true
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "avahi" in ansible_facts.packages )
  - service_exists.stdout_lines is search("avahi-daemon.service", multiline=True)
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_avahi-daemon_disabled

- name: Unit Socket Exists - avahi-daemon.socket
  ansible.builtin.command: systemctl -q list-unit-files avahi-daemon.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "avahi" in ansible_facts.packages )
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_avahi-daemon_disabled

- name: Disable Avahi Server Software - Disable Socket avahi-daemon
  ansible.builtin.systemd:
    name: avahi-daemon.socket
    enabled: false
    state: stopped
    masked: true
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "avahi" in ansible_facts.packages )
  - socket_file_exists.stdout_lines is search("avahi-daemon.socket", multiline=True)
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_avahi-daemon_disabled

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include disable_avahi-daemon

class disable_avahi-daemon {
  service {'avahi-daemon':
    enable => false,
    ensure => 'stopped',
  }
}
Group   Cron and At Daemons   Group contains 1 group and 26 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.
Group   Restrict at and cron to Authorized Users if Necessary   Group contains 8 rules
[ref]   The /etc/cron.allow and /etc/at.allow files contain lists of users who are allowed to use cron and at to delay execution of processes. If these files exist and if the corresponding files /etc/cron.deny and /etc/at.deny do not exist, then only users listed in the relevant allow files can run the crontab and at commands to submit jobs to be run at scheduled intervals. On many systems, only the system administrator needs the ability to schedule jobs. Note that even if a given user is not listed in cron.allow, cron jobs can still be run as that user. The cron.allow file controls only administrative access to the crontab command for scheduling and modifying cron jobs.

To restrict at and cron to only authorized users:
  • Remove the cron.deny file:
    $ sudo rm /etc/cron.deny
  • Edit /etc/cron.allow, adding one line for each user allowed to use the crontab command to create cron jobs.
  • Remove the at.deny file:
    $ sudo rm /etc/at.deny
  • Edit /etc/at.allow, adding one line for each user allowed to use the at command to create at jobs.

Rule   Ensure that /etc/at.deny does not exist   [ref]

The file /etc/at.deny should not exist. Use /etc/at.allow instead.
Rationale:
Access to at should be restricted. It is easier to manage an allow list than a deny list.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_at_deny_not_exist
References:
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:disable
- name: Remove /etc/at.deny
  file:
    path: /etc/at.deny
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - disable_strategy
  - file_at_deny_not_exist
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

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

if [[ -f  /etc/at.deny ]]; then
        rm /etc/at.deny
    fi

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

Rule   Ensure that /etc/cron.deny does not exist   [ref]

The file /etc/cron.deny should not exist. Use /etc/cron.allow instead.
Rationale:
Access to cron should be restricted. It is easier to manage an allow list than a deny list.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_cron_deny_not_exist
References:
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:disable
- name: Remove /etc/cron.deny
  file:
    path: /etc/cron.deny
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - disable_strategy
  - file_cron_deny_not_exist
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

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

if [[ -f  /etc/cron.deny ]]; then
        rm /etc/cron.deny
    fi

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

Rule   Verify Group Who Owns /etc/at.allow file   [ref]

If /etc/at.allow exists, it must be group-owned by root. To properly set the group owner of /etc/at.allow, run the command:
$ sudo chgrp root /etc/at.allow
Rationale:
If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_at_allow
References:
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/at.allow
  file:
    path: /etc/at.allow
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_at_allow
  - 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

chgrp 0 /etc/at.allow

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

Rule   Verify Group Who Owns /etc/cron.allow file   [ref]

If /etc/cron.allow exists, it must be group-owned by root. To properly set the group owner of /etc/cron.allow, run the command:
$ sudo chgrp root /etc/cron.allow
Rationale:
If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_allow
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
disaCCI-000366
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
pcidss42.2.6

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

- name: Ensure group owner 0 on /etc/cron.allow
  file:
    path: /etc/cron.allow
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_cron_allow
  - 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

chgrp 0 /etc/cron.allow

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

Rule   Verify User Who Owns /etc/at.allow file   [ref]

If /etc/at.allow exists, it must be owned by root. To properly set the owner of /etc/at.allow, run the command:
$ sudo chown root /etc/at.allow 
Rationale:
If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_at_allow
References:
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/at.allow
  file:
    path: /etc/at.allow
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_at_allow
  - 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

chown 0 /etc/at.allow

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

Rule   Verify User Who Owns /etc/cron.allow file   [ref]

If /etc/cron.allow exists, it must be owned by root. To properly set the owner of /etc/cron.allow, run the command:
$ sudo chown root /etc/cron.allow 
Rationale:
If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_allow
References:
cis-csc12, 13, 14, 15, 16, 18, 3, 5
cobit5APO01.06, DSS05.04, DSS05.07, DSS06.02
disaCCI-000366
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
pcidss42.2.6

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

- name: Ensure owner 0 on /etc/cron.allow
  file:
    path: /etc/cron.allow
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_cron_allow
  - 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

chown 0 /etc/cron.allow

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

Rule   Verify Permissions on /etc/at.allow file   [ref]

If /etc/at.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/at.allow, run the command:
$ sudo chmod 0640 /etc/at.allow
Rationale:
If the permissions of the at.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_at_allow
References:
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/at.allow
  file:
    path: /etc/at.allow
    mode: u-xs,g-xws,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - 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-xws,o-xwrt /etc/at.allow

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

Rule   Verify Permissions on /etc/cron.allow file   [ref]

If /etc/cron.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/cron.allow, run the command:
$ sudo chmod 0640 /etc/cron.allow
Rationale:
If the permissions of the cron.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_allow
References:
os-srgSRG-OS-000480-GPOS-00227
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Test for existence /etc/cron.allow
  stat:
    path: /etc/cron.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/cron.allow
  file:
    path: /etc/cron.allow
    mode: u-xs,g-xws,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_allow
  - 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-xws,o-xwrt /etc/cron.allow

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

Rule   Verify Group Who Owns cron.d   [ref]

To properly set the group owner of /etc/cron.d, run the command:
$ sudo chgrp root /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 be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_d
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure group owner on /etc/cron.d/
  file:
    path: /etc/cron.d/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_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 -type d -exec chgrp 0 {} \;

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

Rule   Verify Group Who Owns cron.daily   [ref]

To properly set the group owner of /etc/cron.daily, run the command:
$ sudo chgrp root /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 be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_daily
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure group owner on /etc/cron.daily/
  file:
    path: /etc/cron.daily/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_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 -type d -exec chgrp 0 {} \;

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

Rule   Verify Group Who Owns cron.hourly   [ref]

To properly set the group owner of /etc/cron.hourly, run the command:
$ sudo chgrp root /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 be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_hourly
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure group owner on /etc/cron.hourly/
  file:
    path: /etc/cron.hourly/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_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 -type d -exec chgrp 0 {} \;

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

Rule   Verify Group Who Owns cron.monthly   [ref]

To properly set the group owner of /etc/cron.monthly, run the command:
$ sudo chgrp root /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 be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_monthly
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure group owner on /etc/cron.monthly/
  file:
    path: /etc/cron.monthly/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_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 -type d -exec chgrp 0 {} \;

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

Rule   Verify Group Who Owns cron.weekly   [ref]

To properly set the group owner of /etc/cron.weekly, run the command:
$ sudo chgrp root /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 be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_weekly
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure group owner on /etc/cron.weekly/
  file:
    path: /etc/cron.weekly/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_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 -type d -exec chgrp 0 {} \;

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

Rule   Verify Group Who Owns Crontab   [ref]

To properly set the group owner of /etc/crontab, run the command:
$ sudo chgrp root /etc/crontab
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_groupowner_crontab
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
pcidss42.2.6

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

- name: Ensure group owner 0 on /etc/crontab
  file:
    path: /etc/crontab
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_crontab
  - 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

chgrp 0 /etc/crontab

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

Rule   Verify Owner on cron.d   [ref]

To properly set the owner of /etc/cron.d, run the command:
$ sudo chown root /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 be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_d
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure owner on directory /etc/cron.d/
  file:
    path: /etc/cron.d/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_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 -type d -exec chown 0 {} \;

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

Rule   Verify Owner on cron.daily   [ref]

To properly set the owner of /etc/cron.daily, run the command:
$ sudo chown root /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 be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_daily
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure owner on directory /etc/cron.daily/
  file:
    path: /etc/cron.daily/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_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 -type d -exec chown 0 {} \;

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

Rule   Verify Owner on cron.hourly   [ref]

To properly set the owner of /etc/cron.hourly, run the command:
$ sudo chown root /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 be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_hourly
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure owner on directory /etc/cron.hourly/
  file:
    path: /etc/cron.hourly/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_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 -type d -exec chown 0 {} \;

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

Rule   Verify Owner on cron.monthly   [ref]

To properly set the owner of /etc/cron.monthly, run the command:
$ sudo chown root /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 be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_monthly
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure owner on directory /etc/cron.monthly/
  file:
    path: /etc/cron.monthly/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_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 -type d -exec chown 0 {} \;

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

Rule   Verify Owner on cron.weekly   [ref]

To properly set the owner of /etc/cron.weekly, run the command:
$ sudo chown root /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 be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_weekly
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
pcidss42.2.6

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Ensure owner on directory /etc/cron.weekly/
  file:
    path: /etc/cron.weekly/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_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 -type d -exec chown 0 {} \;

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

Rule   Verify Owner on crontab   [ref]

To properly set the owner of /etc/crontab, run the command:
$ sudo chown root /etc/crontab 
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 user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_crontab
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
pcidss42.2.6

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

- name: Ensure owner 0 on /etc/crontab
  file:
    path: /etc/crontab
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_crontab
  - 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

chown 0 /etc/crontab

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

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
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
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:
  - 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:
  - 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
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
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:
  - 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:
  - 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
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
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:
  - 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:
  - 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
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
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:
  - 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:
  - 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
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
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:
  - 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:
  - 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

Rule   Verify Permissions on crontab   [ref]

To properly set the permissions of /etc/crontab, run the command:
$ sudo chmod 0600 /etc/crontab
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_crontab
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
pcidss42.2.6

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

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/crontab
  file:
    path: /etc/crontab
    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:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_crontab
  - 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/crontab

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Mail Server Software   Group contains 1 group and 1 rule
[ref]   Mail servers are used to send and receive email over the network. Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious targets of network attack. Ensure that systems are not running MTAs unnecessarily, and configure needed MTAs as defensively as possible.

Very few systems at any site should be configured to directly receive email over the network. Users should instead use mail client programs to retrieve email from a central server that supports protocols such as IMAP or POP3. However, it is normal for most systems to be independently capable of sending email, for instance so that cron jobs can report output to an administrator. Most MTAs, including Postfix, support a submission-only mode in which mail can be sent from the local system to a central site MTA (or directly delivered to a local account), but the system still cannot receive mail directly over a network.

The alternatives program in Alibaba Cloud Linux 3 permits selection of other mail server software (such as Sendmail), but Postfix is the default and is preferred. Postfix was coded with security in mind and can also be more effectively contained by SELinux as its modular design has resulted in separate processes performing specific actions. More information is available on its website, http://www.postfix.org.
Group   Configure SMTP For Mail Clients   Group contains 1 rule
[ref]   This section discusses settings for Postfix in a submission-only e-mail configuration.

Rule   Disable Postfix Network Listening   [ref]

Edit the file /etc/postfix/main.cf to ensure that only the following inet_interfaces line appears:
inet_interfaces = loopback-only
        
Rationale:
This ensures postfix accepts mail messages (such as cron job reports) from the local system only, and not from the network, which protects it from network attack.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_postfix_network_listening_disabled
References:
cis-csc11, 14, 3, 9
cobit5BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
disaCCI-000382
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
anssiR74
pcidss41.4.2
Group   NFS and RPC   Group contains 2 groups and 1 rule
[ref]   The Network File System is a popular distributed filesystem for the Unix environment, and is very widely deployed. This section discusses the circumstances under which it is possible to disable NFS and its dependencies, and then details steps which should be taken to secure NFS's configuration. This section is relevant to systems operating as NFS clients, as well as to those operating as NFS servers.
Group   Disable All NFS Services if Possible   Group contains 1 group and 1 rule
[ref]   If there is not a reason for the system to operate as either an NFS client or an NFS server, follow all instructions in this section to disable subsystems required by NFS.
Warning:  The steps in this section will prevent a system from operating as either an NFS client or an NFS server. Only perform these steps on systems which do not need NFS at all.
Group   Disable Services Used Only by NFS   Group contains 1 rule
[ref]   If NFS is not needed, disable the NFS client daemons nfslock, rpcgssd, and rpcidmapd.

All of these daemons run with elevated privileges, and many listen for network connections. If they are not needed, they should be disabled to improve system security posture.

Rule   Disable rpcbind Service   [ref]

The rpcbind utility maps RPC services to the ports on which they listen. RPC processes notify rpcbind when they start, registering the ports they are listening on and the RPC program numbers they expect to serve. The rpcbind service redirects the client to the proper port number so it can communicate with the requested service. If the system does not require RPC (such as for NFS servers) then this service should be disabled. The rpcbind service can be disabled with the following command:
$ sudo systemctl mask --now rpcbind.service
Rationale:
If the system does not require rpc based services, it is recommended that rpcbind be disabled to reduce the attack surface.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_service_rpcbind_disabled
References:
pcidss42.2.4


[customizations.services]
masked = ["rpcbind"]

Complexity:low
Disruption:low
Reboot:false
Strategy:disable
- name: Disable rpcbind Service - Collect systemd Services Present in the System
  ansible.builtin.command: systemctl -q list-unit-files --type service
  register: service_exists
  changed_when: false
  failed_when: service_exists.rc not in [0, 1]
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

- name: Disable rpcbind Service - Ensure rpcbind.service is Masked
  ansible.builtin.systemd:
    name: rpcbind.service
    state: stopped
    enabled: false
    masked: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - service_exists.stdout_lines is search("rpcbind.service", multiline=True)
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

- name: Unit Socket Exists - rpcbind.socket
  ansible.builtin.command: systemctl -q list-unit-files rpcbind.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

- name: Disable rpcbind Service - Disable Socket rpcbind
  ansible.builtin.systemd:
    name: rpcbind.socket
    enabled: false
    state: stopped
    masked: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - socket_file_exists.stdout_lines is search("rpcbind.socket", multiline=True)
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include disable_rpcbind

class disable_rpcbind {
  service {'rpcbind':
    enable => false,
    ensure => 'stopped',
  }
}
Group   Network Time Protocol   Group contains 3 rules
[ref]   The Network Time Protocol is used to manage the system clock over a network. Computer clocks are not very accurate, so time will drift unpredictably on unmanaged systems. Central time protocols can be used both to ensure that time is consistent among a network of systems, and that their time is consistent with the outside world.

If every system on a network reliably reports the same time, then it is much easier to correlate log messages in case of an attack. In addition, a number of cryptographic protocols (such as Kerberos) use timestamps to prevent certain types of attacks. If your network does not have synchronized time, these protocols may be unreliable or even unusable.

Depending on the specifics of the network, global time accuracy may be just as important as local synchronization, or not very important at all. If your network is connected to the Internet, using a public timeserver (or one provided by your enterprise) provides globally accurate timestamps which may be essential in investigating or responding to an attack which originated outside of your network.

A typical network setup involves a small number of internal systems operating as NTP servers, and the remainder obtaining time information from those internal servers.

There is a choice between the daemons ntpd and chronyd, which are available from the repositories in the ntp and chrony packages respectively.

The default chronyd daemon can work well when external time references are only intermittently accesible, can perform well even when the network is congested for longer periods of time, can usually synchronize the clock faster and with better time accuracy, and quickly adapts to sudden changes in the rate of the clock, for example, due to changes in the temperature of the crystal oscillator. Chronyd should be considered for all systems which are frequently suspended or otherwise intermittently disconnected and reconnected to a network. Mobile and virtual systems for example.

The ntpd NTP daemon fully supports NTP protocol version 4 (RFC 5905), including broadcast, multicast, manycast clients and servers, and the orphan mode. It also supports extra authentication schemes based on public-key cryptography (RFC 5906). The NTP daemon (ntpd) should be considered for systems which are normally kept permanently on. Systems which are required to use broadcast or multicast IP, or to perform authentication of packets with the Autokey protocol, should consider using ntpd.

Refer to https://www.alibabacloud.com/help/en/elastic-compute-service/latest/alibaba-cloud-ntp-server 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   The Chrony package is installed   [ref]

System time should be synchronized between all systems in an environment. This is typically done by establishing an authoritative time server or set of servers and having all systems synchronize their clocks to them. The chrony package can be installed with the following command:
$ sudo yum install chrony
Rationale:
Time synchronization is important to support time sensitive security mechanisms like Kerberos and also ensures log files have consistent time records across the enterprise, which aids in forensic investigations.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_chrony_installed
References:
ism0988, 1405
osppFMT_SMF_EXT.1
pcidssReq-10.4
os-srgSRG-OS-000355-GPOS-00143
anssiR71
pcidss410.6.1


[[packages]]
name = "chrony"
version = "*"

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
- name: Ensure chrony is installed
  package:
    name: chrony
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSS-Req-10.4
  - PCI-DSSv4-10.6.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_chrony_installed

Complexity:low
Disruption:low
Reboot:false
Strategy:enable
include install_chrony

class install_chrony {
  package { 'chrony':
    ensure => 'installed',
  }
}

Rule   A remote time server for Chrony is configured   [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. Add or edit server or pool lines to /etc/chrony.conf as appropriate:
server <remote-server>
Multiple servers may be configured.
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_specify_remote_server
References:
disaCCI-000160, CCI-001891
ism0988, 1405
nistCM-6(a), AU-8(1)(a)
pcidssReq-10.4.3
os-srgSRG-OS-000355-GPOS-00143
anssiR71
pcidss410.6.2

Complexity:low
Disruption:low
Reboot:false
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.3
  - PCI-DSSv4-10.6.2
  - chronyd_specify_remote_server
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_multiple_time_servers # promote to variable
  set_fact:
    var_multiple_time_servers: !!str 0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org
  tags:
    - always

- name: Detect if chrony is already configured with pools or servers
  find:
    path: /etc
    patterns: chrony.conf
    contains: ^[\s]*(?:server|pool)[\s]+[\w]+
  register: chrony_servers
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"chrony" in ansible_facts.packages'
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.3
  - PCI-DSSv4-10.6.2
  - chronyd_specify_remote_server
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure remote time servers
  lineinfile:
    path: /etc/chrony.conf
    line: server {{ item }}
    state: present
    create: true
  loop: '{{ var_multiple_time_servers.split(",") }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"chrony" in ansible_facts.packages'
  - chrony_servers.matched == 0
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.3
  - PCI-DSSv4-10.6.2
  - chronyd_specify_remote_server
  - 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 chrony; }; then

var_multiple_time_servers='0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org'


config_file="/etc/chrony.conf"

if ! grep -q '^[[:space:]]*\(server\|pool\)[[:space:]]\+[[:graph:]]\+' "$config_file" ; then
  if ! grep -q '#[[:space:]]*server' "$config_file" ; then
    for server in $(echo "$var_multiple_time_servers" | tr ',' '\n') ; do
      printf '\nserver %s' "$server" >> "$config_file"
    done
  else
    sed -i 's/#[ \t]*server/server/g' "$config_file"
  fi
fi

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

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
References:
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   Obsolete Services   Group contains 3 groups and 4 rules
[ref]   This section discusses a number of network-visible services which have historically caused problems for system security, and for which disabling or severely limiting the service has been the best available guidance for some time. As a result of this, many of these services are not installed as part of Alibaba Cloud Linux 3 by default.

Organizations which are running these services should switch to more secure equivalents as soon as possible. If it remains absolutely necessary to run one of these services for legacy reasons, care should be taken to restrict the service as much as possible, for instance by configuring host firewall software such as iptables to restrict access to the vulnerable service to only those remote hosts which have a known need to use it.
Group   Xinetd   Group contains 1 rule
[ref]   The xinetd service acts as a dedicated listener for some network services (mostly, obsolete ones) and can be used to provide access controls and perform some logging. It has been largely obsoleted by other features, and it is not installed by default. The older Inetd service is not even available as part of Alibaba Cloud Linux 3.

Rule   Uninstall xinetd Package   [ref]

The xinetd package can be removed with the following command:
$ sudo yum erase xinetd
Rationale:
Removing the xinetd package decreases the risk of the xinetd service's accidental (or intentional) activation.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_xinetd_removed