Verify Group Who Owns /etc/security/opasswd.old File

Description

To properly set the group owner of /etc/security/opasswd.old, run the command:

$ sudo chgrp root /etc/security/opasswd.old

Rationale

The /etc/security/opasswd.old file stores backups of old passwords to prevent password reuse. Protection of this file is critical for system security.

Remediation

Shell script

The following script can be run on the host to remediate the issue.

#!/bin/bash

newgroup=""
if getent group "0" >/dev/null 2>&1; then
  newgroup="0"
fi

if [[ -z "${newgroup}" ]]; then
  >&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/security/opasswd.old" | grep -E -w -q "0"; then
    chgrp --no-dereference "$newgroup" /etc/security/opasswd.old
fi

fi

Ansible playbook

The following playbook can be run with Ansible to remediate the issue.

- name: Set the file_groupowner_etc_security_opasswd_old_newgroup variable if represented
    by gid
  ansible.builtin.set_fact:
    file_groupowner_etc_security_opasswd_old_newgroup: '0'
  tags:
  - configure_strategy
  - file_groupowner_etc_security_opasswd_old
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /etc/security/opasswd.old
  ansible.builtin.stat:
    path: /etc/security/opasswd.old
  register: file_exists
  tags:
  - configure_strategy
  - file_groupowner_etc_security_opasswd_old
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner on /etc/security/opasswd.old
  ansible.builtin.file:
    path: /etc/security/opasswd.old
    follow: false
    group: '{{ file_groupowner_etc_security_opasswd_old_newgroup }}'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - configure_strategy
  - file_groupowner_etc_security_opasswd_old
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed