Title

The Red Hat Enterprise Linux operating system must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS. (Cat II impact)

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 more securely authenticate the remote mount request.

Check Content

Verify "AUTH_GSS" is being used to authenticate NFS mounts. To check if the system is importing an NFS file system, look for any entries in the "/etc/fstab" file that have a file system type of "nfs" with the following command: # cat /etc/fstab | grep nfs 192.168.21.5:/mnt/export /data1 nfs4 rw,sync ,soft,sec=krb5:krb5i:krb5p 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 Text

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 "krb5:krb5i:krb5p".

Additional Identifiers

Rule ID: SV-204626r603261_rule

Vulnerability ID: V-204626

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

Expert Comments

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