Vulnerability Discussion

The "su" program allows commands to be run with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such commands is considered a good security practice.

Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000312-GPOS-00123

Check

Verify RHEL 10 requires users to be members of the "wheel" group to run "su".

Verify the configuration with the following command:

$ sudo grep pam_wheel /etc/pam.d/su
auth required pam_wheel.so use_uid

If a line for "pam_wheel.so" does not exist or is commented out, this is a finding.

Fix

Configure RHEL 10 to require users to be in the "wheel" group to run the "su" command.

Edit the configuration file:

$ sudo vi /etc/pam.d/su

Add the following lines:

auth required pam_wheel.so use_uid
$ sed '/^[[:space:]]*#[[:space:]]*auth[[:space:]]\+required[[:space:]]\+pam_wheel\.so[[:space:]]\+use_uid$/s/^[[:space:]]*#//' -i /etc/pam.d/su

If necessary, create a "wheel" group and add administrative users to the group.