RHEL 9 must restrict the use of the "su" command.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258088	RHEL-09-432035	SV-258088r997082_rule		Medium

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

STIG	Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2024-06-04

Details

Check Text ( C-61829r926249_chk )
Verify that RHEL 9 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 Text (F-61753r926250_fix)
Configure RHEL 9 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" $ 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 Text (F-61753r926250_fix)

Configure RHEL 9 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"

$ 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.