Amazon Linux 2023 must restrict the use of the "su" command.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-274151	SRG-OS-000312-GPOS-00123	AZLX-23-002440	SV-274151r1120441_rule	2025-07-15	1

Description
The "su" program allows to run commands 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.

ℹ️ Check
Verify Amazon Linux 2023 requires uses to be members of the "wheel" group with the following command: $ 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 Amazon Linux 2023 to require users to be in the "wheel" group to run "su" command. In file "/etc/pam.d/su", uncomment the following line: "#auth required pam_wheel.so use_uid" $ sudo 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.

✔️ Fix

Configure Amazon Linux 2023 to require users to be in the "wheel" group to run "su" command. In file "/etc/pam.d/su", uncomment the following line: "#auth required pam_wheel.so use_uid" $ sudo 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.