Title

The nosuid option must be enabled on all NFS client mounts. (Cat II impact)

Discussion

Enabling the nosuid mount option prevents the system from granting owner or group-owner privileges to programs with the setuid or setgid bit set. If the system does not restrict this access, users with unprivileged access to the local system may be able to acquire privileged access by executing setuid or setgid files located on the mounted NFS file system.

Check Content

Check the system for NFS mounts not using the nosuid option. Procedure: # mount -v | grep " type nfs " | grep -v nosetuid OR # grep nfs /etc/mnttab | grep -v nosuid | grep -v :vold If the mounted file systems do not have the nosetuid/nosuid option, this is a finding. NOTE: Mount options for the volume management daemon (vold) are controlled by the /etc/rmmount.conf file.

Fix Text

Edit /etc/vfstab and add the nosuid option for all NFS file systems. Remount the NFS file systems to make the change take effect.

Additional Identifiers

Rule ID: SV-227922r603266_rule

Vulnerability ID: V-227922

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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