Title

File systems that are being imported via Network File System (NFS) must be mounted to prevent files with the setuid and setguid bit set from being executed. (Cat II impact)

Discussion

The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.

Check Content

Verify file systems that are being Network File System (NFS) imported are mounted with the "nosuid" option. Find the file system(s) that contain the directories being exported with the following command: # grep nfs /etc/fstab | grep nosuid UUID=e06097bb-cfcd-437b-9e4d-a691f5662a7d /store nfs rw,nosuid 0 0 If a file system found in "/etc/fstab" refers to NFS and it does not have the "nosuid" option set, this is a finding.

Fix Text

Configure the "/etc/fstab" to use the "nosuid" option on file systems that are being imported via Network File System (NFS).

Additional Identifiers

Rule ID: SV-215014r610931_rule

Vulnerability ID: V-215014

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

Expert Comments

CCIs tied to check.

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