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V-271723

CAT II (Medium)

OL 9 must restrict the use of the su command.

Rule ID

SV-271723r1091881_rule

STIG

Oracle Linux 9 Security Technical Implementation Guide

Version

V1R5

CCIs

CCI-002165

Discussion

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.

Check Content

Verify that OL 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

Configure OL 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"

Or use the following command to update /etc/pam.d/su 

$ 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.

$ grep wheel /etc/group