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1.1.2.4.2 Ensure nosuid option set on /var/tmp partition

Information

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

WARNING This option is worthless if a publicly available suid or sgid wrapper is installed on your system. It is set automatically when the user does not have super-user privileges.

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

- IF - a separate partition exists for /var/tmp.

Edit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /var/tmp partition.

Example:

<device> /var/tmp <fstype> rw,nosuid,noexec 0 0

Run the following command to remount /var/tmp with the configured options:

# mount -u -o nosuid /var/tmp

See Also

https://workbench.cisecurity.org/benchmarks/19044

Item Details

Category: ACCESS CONTROL, MEDIA PROTECTION

References: 800-53|AC-3, 800-53|AC-5, 800-53|AC-6, 800-53|MP-2, CSCv7|14.6

Plugin: Unix

Control ID: a6e1901ab933214b9171385a159651ced9bfc5c157fccfc91da83a732430cc4f