AlmaLinux OS 9 SSH public host key files must have mode 0644 or less permissive.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-269266 | ALMA-09-021030 | SV-269266r1050148_rule | CCI-000366 | medium |
| Description | ||||
| If a public host key file is modified by an unauthorized user, the SSH service may be compromised. Whilst public keys are publicly readable, they should not be writeable by nonowners. | ||||
| STIG | Date | |||
| CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide | 2025-05-22 | |||
Details
Check Text (C-269266r1050148_chk)
Verify the SSH public host key files have a mode of "0644" or less permissive with the following command:
Note: SSH public key files may be found in other directories on the system depending on the installation.
$ stat -c "%#a %n" /etc/ssh/ssh_host*key.pub
0644 /etc/ssh/ssh_host_ecdsa_key.pub
0644 /etc/ssh/ssh_host_rsa_key.pub
If any public key has a mode more permissive than "0644", this is a finding.
Fix Text (F-73198r1048175_fix)
Change the mode of public host key files under "/etc/ssh" to "0644" with the following command:
$ chmod 0644 /etc/ssh/*key.pub
Restart the SSH daemon for the changes to take effect:
$ systemctl restart sshd.service