Verify Who Owns /etc/shells File
Description
To properly set the owner of /etc/shells
, run the command:
$ sudo chown root /etc/shells
Rationale
The /etc/shells
file contains the list of full pathnames to shells on the system.
Since this file is used by many system programs this file should be protected.
Shell script
The following script can be run on the host to remediate the issue.
#!/bin/bash
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z ${newown} ]]; then
echo "0 is not a defined user on the system"
exit 1
fi
chown $newown /etc/shells
Ansible playbook
The following playbook can be run with Ansible to remediate the issue.
- name: Set the file_owner_etc_shells_newown variable if represented by uid
set_fact:
file_owner_etc_shells_newown: '0'
tags:
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_owner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shells
stat:
path: /etc/shells
register: file_exists
tags:
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_owner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/shells
file:
path: /etc/shells
owner: '{{ file_owner_etc_shells_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_owner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed