Vulnerability Discussion

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

Check

Verify the SUSE operating system SSH daemon private host key files have mode "0640" or less permissive.

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

> 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 "0640", this is a finding.

Fix

Configure the mode of the SUSE operating system SSH daemon private host key files under "/etc/ssh" to "0640" with the following command:

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