Ubuntu 24.04 LTS must not allow unattended or automatic login via SSH.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-270717 | UBTU-24-300031 | SV-270717r1067177_rule | CCI-000366 | high |
| Description | ||||
| Failure to restrict system access to authenticated users negatively impacts Ubuntu 24.04 LTS security. | ||||
| STIG | Date | |||
| Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide | 2025-05-16 | |||
Details
Check Text (C-270717r1067177_chk)
Verify unattended or automatic login via SSH is disabled with the following command:
$ egrep -r '(Permit(.*?)(Passwords|Environment))' /etc/ssh/sshd_config
PermitEmptyPasswords no
PermitUserEnvironment no
If the "PermitEmptyPasswords" or "PermitUserEnvironment" keywords are set to a value other than "no", are commented out, are both missing, or conflicting results are returned, this is a finding.
Fix Text (F-74651r1066639_fix)
Configure Ubuntu 24.04 LTS to allow the SSH daemon to not allow unattended or automatic login to the system.
Add or edit the following lines in the "/etc/ssh/sshd_config" file:
PermitEmptyPasswords no
PermitUserEnvironment no
Restart the SSH daemon for the changes to take effect:
$ sudo systemctl restart sshd.service