Verify Group Who Owns Backup passwd File

Description

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.

Remediation

Shell script

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

#!/bin/bash

chgrp -L 0 /etc/passwd-

Ansible playbook

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

- 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