RHEL 9 must be configured so that the Network File System (NFS) is configured to use RPCSEC

RHEL 9 must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-257853	RHEL-09-231060	SV-257853r991589_rule		Medium

Description
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.

STIG	Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2024-06-04

Details

Check Text ( C-61594r925544_chk )
Verify RHEL 9 has the "sec" option configured for all NFS mounts with the following command: Note: If no NFS mounts are configured, this requirement is Not Applicable. $ 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.

Check Text ( C-61594r925544_chk )

Verify RHEL 9 has the "sec" option configured for all NFS mounts with the following command:

Note: If no NFS mounts are configured, this requirement is Not Applicable.

$ 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 Text (F-61518r925545_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".