STIGUI
V-271771CAT II — Medium severitySV-271771r1208733_rule

OL 9 SSH private host key files must have mode 0600 or less permissive.

Rule version OL09-00-002502 · STIG v1 · 2026-08-21

Discussion

If an unauthorized user obtains the private SSH host key file, the host could be impersonated.

Check

Verify that OL 9 SSH private host key files have a mode of "0600" or less permissive with the following command:

$ ls -l /etc/ssh/*_key 600 /etc/ssh/ssh_host_dsa_key 600 /etc/ssh/ssh_host_ecdsa_key 600 /etc/ssh/ssh_host_ed25519_key 600 /etc/ssh/ssh_host_rsa_key

If any private host key file has a mode more permissive than "0600", this is a finding.

Fix

Configure the mode of SSH private host key files under "/etc/ssh" to "0600" with the following command:

$ sudo chmod 0600 /etc/ssh/ssh_host*key

Restart the SSH daemon for the changes to take effect:

$ sudo systemctl restart sshd.service

Identifiers

Group ID
V-271771
Group title
SRG-OS-000480-GPOS-00227
Rule ID
SV-271771r1208733_rule
Check ID
C-75821r1208351_chk
Fix ID
F-75728r1208352_fix