# CIS Ubuntu 14.04 LTS - 5.6 Ensure access to the su command is restricted

> Verify access to the su command is restricted to the wheel group via PAM configuration

- Skill: `cyberstrikeus/cis-ubuntu-14-04-lts-5-6-ensure-access-to-the-su-command-is-` (Agent Skill)
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- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu-14-04-lts-5-6-ensure-access-to-the-su-command-is-

---


# 5.6 Ensure access to the su command is restricted (Scored)

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

The `su` command allows a user to run a command or shell as another user. The program has been superseded by `sudo`, which allows for more granular control over privileged access. Normally, the `su` command can be executed by any user. By uncommenting the `pam_wheel.so` statement in `/etc/pam.d/su`, the `su` command will only allow users in the wheel group to execute `su`.

## Rationale

Restricting the use of `su`, and using `sudo` in its place, provides system administrators better control of the escalation of user privileges to execute privileged commands. The sudo utility also provides a better logging and audit mechanism, as it can log each command executed via `sudo`, whereas `su` can only record that a user executed the `su` program.

## Audit Procedure

Run the following command and verify output includes matching line:

```bash
grep pam_wheel.so /etc/pam.d/su
```

Run the following command and verify users in `wheel` group match site policy:

```bash
grep wheel /etc/group
```

## Expected Result

```
auth required pam_wheel.so
wheel:x:10:root,<user list>
```

## Remediation

Add the following line to the `/etc/pam.d/su` file:

```
auth required pam_wheel.so
```

Create a comma separated list of users in the wheel statement in the `/etc/group` file:

```
wheel:x:10:root,<user list>
```

## Default Value

su is available to all users by default.

## References

- CIS Controls: 5.1 - Minimize And Sparingly Use Administrative Privileges

## Profile

- Level 1 - Server
- Level 1 - Workstation