Title

The SSH client must be configured to only use the SSHv2 protocol. (Cat II impact)

Discussion

SSHv1 is not a DoD-approved protocol and has many well-known vulnerability exploits. Exploits of the SSH client could provide access to the system with the privileges of the user running the client.

Check Content

Check the SSH client configuration for allowed protocol versions. # grep -i protocol /etc/ssh/ssh_config | grep -v '^#' If the returned protocol configuration allows versions less than 2, this is a finding.

Fix Text

Edit the /etc/ssh/ssh_config file and add or edit a Protocol configuration line that does not allow versions less than 2.

Additional Identifiers

Rule ID: SV-227891r603266_rule

Vulnerability ID: V-227891

Group Title: SRG-OS-000074

Expert Comments

CCIs tied to check.

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