Rule ID
SV-215234r1184573_rule
Version
V3R2
CCIs
The nosuid mount option causes the system to not execute setuid files with owner privileges. This option must be used for mounting any file system not containing approved setuid files. Executing setuid files from untrusted file systems, or file systems not containing approved setuid files, increases the opportunity for unprivileged users to attain unauthorized administrative access.
Obtain a list of NFS file systems that contain approved "setuid" or "setgid" files from the information system security officer (ISSO)/information system security officer (ISSM). Check the "nosuid" mount option is used on all NFS file systems that do not contain approved "setuid" or "setgid" files: # mount | grep -E "options|nfs|---" node mounted mounted over vfs date options -------- --------------- --------------- ------ ------------ --------------- nfs.example.com /path/to/directory1 /mnt_1 nfs3 Nov 05 14:11 ro,bg,hard,intr,nosuid,sec=sys nfs.example.com /path/to/directory2 /mnt_2 nfs3 Nov 05 14:12 ro,bg,hard,intr,sec=sys If the NFS mounts do not show the "nosuid" setting in their "options" fields, along with other mount options, this is a finding.
For each NFS file systems that does not contain approved "setuid" or "setgid" files, add the "nosuid" option, along with other mount options, to the "options" field in "/etc/filesystems" using the following command: # chfs -a options=ro,bg,hard,intr,nosuid,sec=sys <NFS_mount_point> Note that the other mount options (other than the nosuid options) may be different among NFS mounts.