Title

The SSH client must be configured to only use FIPS 140-2 approved ciphers. (Cat II impact)

Discussion

DoD information systems are required to use FIPS 140-2 approved ciphers. SSHv2 ciphers meeting this requirement are 3DES and AES. Satisfies: SRG-OS-000033, SRG-OS-000505, SRG-OS-000555

Check Content

Check the SSH client configuration for allowed ciphers. # grep -i ciphers /etc/ssh/ssh_config | grep -v '^#' If no lines are returned, the returned ciphers list contains any cipher not starting with 3des or aes, this is a finding.

Fix Text

Edit /etc/ssh/ssh_config and add or edit the "Ciphers" line. Only include ciphers that start with "3des" or "aes" and do not contain "cbc". For the list of available ciphers for the particular version of your software, consult the ssh_config manpage.

Additional Identifiers

Rule ID: SV-227896r603266_rule

Vulnerability ID: V-227896

Group Title: SRG-OS-000033

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.