TOSS 5 must not allow users to override SSH environment variables.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-282758 | TOSS-05-000246 | SV-282758r1201254_rule | CCI-000366 | medium |
| Description | ||||
| SSH environment options potentially allow users to bypass access restriction in some configurations. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide | 2026-04-01 | |||
Details
Check Text (C-282758r1201254_chk)
Verify unattended or automatic logon via SSH is disabled using 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.
Fix Text (F-87224r1201253_fix)
Configure the TOSS 5 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
Restart the SSH daemon for the setting to take effect:
$ sudo systemctl restart sshd.service