STIGUI
V-261294CAT II — Medium severitySV-261294r996359_rule

SLEM 5 SSH daemon private host key files must have mode 640 or less permissive.

Rule version SLEM-05-232045 · STIG v1 · 2026-08-20

Discussion

If an unauthorized user obtains the private SSH host key file, the host could be impersonated.

Check

Verify SLEM 5 SSH daemon private host key files have mode "640" or less permissive.

The following command will find all SSH private key files on the system with the following command:

     > sudo find / -name '*ssh_host*key' -exec ls -lL {} \;

Check the mode of the private host key files under "/etc/ssh" file with the following command:

     > find /etc/ssh -name 'ssh_host*key' -exec stat -c "%a %n" {} \;
     640 /etc/ssh/ssh_host_rsa_key
     640 /etc/ssh/ssh_host_dsa_key
     640 /etc/ssh/ssh_host_ecdsa_key
     640 /etc/ssh/ssh_host_ed25519_key

If any file has a mode more permissive than "640", this is a finding.

Fix

Configure the mode of SLEM 5 SSH daemon private host key files under "/etc/ssh" to "640" with the following command:

      > sudo chmod 640 /etc/ssh/ssh_host*key

Identifiers

Group ID
V-261294
Group title
SRG-OS-000480-GPOS-00227
Rule ID
SV-261294r996359_rule
Check ID
C-65023r996358_chk
Fix ID
F-64931r995748_fix