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-258088r1050789_rule | CCI-004895 | 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 | 2025-05-14 | |||
Details
Check Text (C-258088r1050789_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.