STIGQter: STIG Summary: Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide Version: 1 Release: 1 Benchmark Date: 26 Mar 2026:

TOSS 5 SSH private host key files must have mode 0640 or less permissive.

DISA Rule

SV-282709r1201369_rule

Vulnerability Number

V-282709

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

TOSS-05-000253

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 "0640" using the following command:

$ sudo chmod 0640 /etc/ssh/ssh_host*key

Restart the SSH daemon for the changes to take effect.

$ sudo systemctl restart sshd.service

Check Contents

Verify the SSH private host key files have a mode of "0640" or less permissive using the following command:

$ ls -l /etc/ssh/*_key

640 /etc/ssh/ssh_host_dsa_key
640 /etc/ssh/ssh_host_ecdsa_key
640 /etc/ssh/ssh_host_ed25519_key
640 /etc/ssh/ssh_host_rsa_key

If any private host key file has a mode more permissive than "0640", this is a finding.

Vulnerability Number

V-282709

Documentable

False

Rule Version

TOSS-05-000253

Severity Override Guidance

Verify the SSH private host key files have a mode of "0640" or less permissive using the following command:

$ ls -l /etc/ssh/*_key

640 /etc/ssh/ssh_host_dsa_key
640 /etc/ssh/ssh_host_ecdsa_key
640 /etc/ssh/ssh_host_ed25519_key
640 /etc/ssh/ssh_host_rsa_key

If any private host key file has a mode more permissive than "0640", this is a finding.

Check Content Reference

M

Target Key

5738