Title

The Red Hat Enterprise Linux operating system must mount /dev/shm with the nosuid option. (Cat III 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 that the "nosuid" option is configured for /dev/shm. Check that the operating system is configured to use the "nosuid" option for /dev/shm with the following command: # cat /etc/fstab | grep /dev/shm | grep nosuid tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0 If the "nosuid" option is not present on the line for "/dev/shm", this is a finding. Verify "/dev/shm" is mounted with the "nosuid" option: # mount | grep "/dev/shm" | grep nosuid If no results are returned, this is a finding.

Fix Text

Configure the "/etc/fstab" to use the "nosuid" option for all lines containing "/dev/shm".

Additional Identifiers

Rule ID: SV-218109r603264_rule

Vulnerability ID: V-218109

Group Title: SRG-OS-000368

Expert Comments

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