STIGQter: STIG Summary: Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide Version: 2 Release: 6 Benchmark Date: 01 Jul 2026:

The TOSS SSH daemon must perform strict mode checking of home directory configuration files.

DISA Rule

SV-253106r991589_rule

Vulnerability Number

V-253106

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

TOSS-04-040650

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

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

Check Contents

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.

Vulnerability Number

V-253106

Documentable

False

Rule Version

TOSS-04-040650

Severity Override Guidance

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.

Check Content Reference

M

Target Key

5469