Verify Permissions on crontab
Description
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.
Shell script
The following script can be run on the host to remediate the issue.
#!/bin/bash
# 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
Ansible playbook
The following playbook can be run with Ansible to remediate the issue.
- 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
