Details

The nosuid mount option specifies that the filesystem cannot contain setuid files.

Rationale:

Since the /var/tmp filesystem is only intended for temporary file storage, set this option to ensure that users cannot create setuid files in /var/tmp .

Solution

For existing /var/tmp partitions, edit the /etc/fstab file and add nosuid to the fourth field (mounting options) of the /var/tmp entry. See the fstab(5) manual page for more information.
Run the following command to remount /var/tmp :

# mount -o remount,nosuid /var/tmp

Supportive Information

The following resource is also helpful.

• https://workbench.cisecurity.org/files/3490https://workbench.cisecurity.org/files/3490

This security hardening control applies to the following category of controls within NIST 800-53: Access Control, Configuration Management, Identification and Authentication, Media Protection.This control applies to the following type of system Unix.

References

• 800-53|AC-3
• 800-53|CM-1
• 800-53|CM-2
• 800-53|CM-6
• 800-53|CM-7
• 800-53|IA-5
• 800-53|MP-2
• CSCv7|5.1

Source

• Tenable.com/audits