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.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-215014	UBTU-16-010820	SV-215014r508033_rule		Medium

Description
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.

STIG	Date
Canonical Ubuntu 16.04 LTS Security Technical Implementation Guide	2020-09-03

Details

Check Text ( C-16213r284910_chk )
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.

Check Text ( C-16213r284910_chk )

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 (F-16211r284911_fix)
Configure the "/etc/fstab" to use the "nosuid" option on file systems that are being imported via Network File System (NFS).