The TOSS SSH daemon must not allow Kerberos authentication, except to fulfill documented and validated mission requirements.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-252944 | TOSS-04-010420 | SV-252944r991589_rule | Medium |
| Description |
| Configuring these settings for the SSH daemon provides additional assurance that remote logon via SSH will not use unused methods of authentication, even in the event of misconfiguration elsewhere. |
| STIG | Date |
| Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide | 2025-05-08 |
Details
| Check Text (C-56397r824154_chk) |
| Verify the SSH daemon does not allow Kerberos authentication with the following command: $ sudo grep -i KerberosAuthentication /etc/ssh/sshd_config KerberosAuthentication no If the value is returned as "yes", the returned line is commented out, no output is returned, or has not been documented with the ISSO, this is a finding. |
| Fix Text (F-56347r824155_fix) |
| Configure the SSH daemon to not allow Kerberos authentication. Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "no": KerberosAuthentication 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 |