Vulnerability Discussion
When an NFS server is configured to use RPCSEC_SYS, a selected userid and groupid are used to handle requests from the remote user. The userid and groupid could mistakenly or maliciously be set incorrectly. The RPCSEC_GSS method of authentication uses certificates on the server and client systems to authenticate the remote mount request more securely.
Check
If no NFS mounts are configured, this requirement is Not Applicable.
Verify that OL 9 has the "sec" option configured for all NFS mounts with the following command:
$ cat /etc/fstab | grep nfs
192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5p:krb5i:krb5
If the system is mounting file systems via NFS and has the sec option without the "krb5:krb5i:krb5p" settings, the "sec" option has the "sys" setting, or the "sec" option is missing, this is a finding.
Fix
Update the "/etc/fstab" file so the option "sec" is defined for each NFS mounted file system and the "sec" option does not have the "sys" setting.
Ensure the "sec" option is defined as "krb5p:krb5i:krb5".