Title

The Red Hat Enterprise Linux operating system must be configured so that the SSH private host key files have mode 0640 or less permissive. (Cat II impact)

Discussion

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

Check Content

Verify the SSH private host key files have mode "0640" or less permissive. The following command will find all SSH private key files on the system and list their modes: # find / -name '*ssh_host*key' | xargs ls -lL -rw-r----- 1 root ssh_keys 112 Apr 1 11:59 ssh_host_dsa_key -rw-r----- 1 root ssh_keys 202 Apr 1 11:59 ssh_host_key -rw-r----- 1 root ssh_keys 352 Apr 1 11:59 ssh_host_rsa_key If any file has a mode more permissive than "0640", this is a finding.

Fix Text

Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: # chmod 0640 /path/to/file/ssh_host*key

Additional Identifiers

Rule ID: SV-204597r991589_rule

Vulnerability ID: V-204597

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

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