Vulnerability Discussion
Untrusted Certificate Authorities (CA) can issue certificates, but they may be issued by organizations or individuals that seek to compromise DoD systems or by organizations with insufficient security controls. If the CA used for verifying the certificate is not a DoD-approved CA, trust of this CA has not been established.
The DoD will only accept PKI-certificates obtained from a DoD-approved internal or external certificate authority. Reliance on CAs for the establishment of secure sessions includes, for example, the use of SSL/TLS certificates.
Check
Verify the directory containing the root certificates for the Ubuntu operating system only contains certificate files for DoD PKI-established certificate authorities by iterating over all files in the '/etc/ssl/certs' directory and checking if, at least one, has the subject matching "DOD ROOT CA".
If none is found, this is a finding.
Fix
Add at least one DOD certificate authority to the '/usr/local/share/ca-certificates' directory, then run the 'update-ca-certificates' command.