Verify Group Ownership on SSH Server Private *_key Key Files
An XCCDF Rule
Description
SSH server private keys, files that match the /etc/ssh/*_key glob, must be
group-owned by ssh_keys group.
Rationale
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
- ID
- xccdf_org.ssgproject.content_rule_file_groupownership_sshd_private_key
- Severity
- Medium
- References
- Updated
Remediation - Shell Script
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then
find /etc/ssh/ -maxdepth 1 -type f ! -group ssh_keys -regex '^.*_key$' -exec chgrp ssh_keys {} \;
else
Remediation - Ansible
- name: Find /etc/ssh/ file(s) matching ^.*_key$
command: find -H /etc/ssh/ -maxdepth 1 -type f ! -group ssh_keys -regex "^.*_key$"
register: files_found
changed_when: false
failed_when: false
check_mode: false