RHEL 9 SSH daemon must perform strict mode checking of home directory configuration files.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-258008 | RHEL-09-255160 | SV-258008r1045075_rule | Medium |
| Description |
| If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user. |
| STIG | Date |
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2024-12-04 |
Details
| Check Text (C-61749r952211_chk) |
| Verify the SSH daemon performs strict mode checking of home directory configuration files 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*strictmodes' StrictModes yes If the "StrictModes" keyword is set to "no", the returned line is commented out, or no output is returned, this is a finding. |
| Fix Text (F-61673r1045074_fix) |
| Configure the SSH daemon to perform strict mode checking of home directory configuration files. Add the following line to "/etc/ssh/sshd_config" or to a file in "/etc/ssh/sshd_config.d", or uncomment the line and set the value to "yes": StrictModes yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |