RHEL 8 must not allow users to override SSH environment variables.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-230330 | RHEL-08-010830 | SV-230330r1017141_rule | Medium |
| Description |
| SSH environment options potentially allow users to bypass access restriction in some configurations. |
| STIG | Date |
| Red Hat Enterprise Linux 8 Security Technical Implementation Guide | 2024-11-25 |
Details
| Check Text (C-32999r951609_chk) |
| Verify that unattended or automatic logon 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-32974r567737_fix) |
| Configure RHEL 8 to allow the SSH daemon to not allow unattended or automatic logon 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 |