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 private host key files must have mode 0600 or less permissive.

DISA Rule

SV-253107r991589_rule

Vulnerability Number

V-253107

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

TOSS-04-040660

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

Configure the mode of SSH private host key files under "/etc/ssh" to "0600" with the following command:

$ sudo chmod 0600 /etc/ssh/ssh_host*key

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 private host key files have mode "0600" or less permissive with the following command:

$ sudo ls -l /etc/ssh/ssh_host*key

-rw------- 1 root ssh_keys 668 Nov 28 06:43 ssh_host_dsa_key
-rw------- 1 root ssh_keys 582 Nov 28 06:43 ssh_host_key
-rw------- 1 root ssh_keys 887 Nov 28 06:43 ssh_host_rsa_key

If any private host key file has a mode more permissive than "0600", this is a finding.

Vulnerability Number

V-253107

Documentable

False

Rule Version

TOSS-04-040660

Severity Override Guidance

Verify the SSH private host key files have mode "0600" or less permissive with the following command:

$ sudo ls -l /etc/ssh/ssh_host*key

-rw------- 1 root ssh_keys 668 Nov 28 06:43 ssh_host_dsa_key
-rw------- 1 root ssh_keys 582 Nov 28 06:43 ssh_host_key
-rw------- 1 root ssh_keys 887 Nov 28 06:43 ssh_host_rsa_key

If any private host key file has a mode more permissive than "0600", this is a finding.

Check Content Reference

M

Target Key

5469