OL 8 must not allow users to override SSH environment variables.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-248650 | OL08-00-010830 | SV-248650r991591_rule | CCI-000366 | high |
| Description | ||||
| SSH environment options potentially allow users to bypass access restriction in some configurations. | ||||
| STIG | Date | |||
| Oracle Linux 8 Security Technical Implementation Guide | 2025-05-13 | |||
Details
Check Text (C-248650r991591_chk)
Verify that unattended or automatic login via SSH is disabled with the following command:
$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*permituserenvironment'
PermitUserEnvironment no
If "PermitUserEnvironment" is set to "yes", is missing completely, or is commented out, this is a finding.
If conflicting results are returned, this is a finding.
Fix Text (F-52038r779515_fix)
Configure OL 8 to allow the SSH daemon to not allow unattended or automatic login to the system.
Add or edit the following line in the "/etc/ssh/sshd_config" file:
PermitUserEnvironment no
The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command:
$ sudo systemctl restart sshd.service