The TOSS SSH daemon must perform strict mode checking of home directory configuration files.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-253106 | TOSS-04-040650 | SV-253106r991589_rule | CCI-000366 | medium |
| Description | ||||
| If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-253106r991589_chk)
Verify the SSH daemon performs strict mode checking of home directory configuration files with the following command:
$ sudo grep -i strictmodes /etc/ssh/sshd_config
StrictModes yes
If "StrictModes" is set to "no", is missing, or the returned line is commented out, this is a finding.
Fix Text (F-56509r824989_fix)
Configure SSH to perform strict mode checking of home directory configuration files. Uncomment the "StrictModes" keyword in "/etc/ssh/sshd_config" and set the value to "yes":
StrictModes yes
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