Cis Ubuntu1604 V200 4 1 4

---
name: cis-ubuntu1604-v200-4-1-4
description: "Ensure events that modify user/group information are collected"
category: cis-logging
version: "2.0.0"
author: cyberstrike-official
tags: [cis, ubuntu, linux, ubuntu-16.04, auditd, logging]
cis_id: "4.1.4"
cis_benchmark: "CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0"
tech_stack: [ubuntu, linux]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 - Control 4.1.4

## Profile

- **Level:** 2 - Server
- **Level:** 2 - Workstation
- **Assessment Status:** Automated

## Description

Record events affecting the group, passwd (user IDs), shadow and gshadow (passwords) or /etc/security/opasswd (old passwords, based on remember parameter in the PAM configuration) files. The parameters in this section will watch the files to see if they have been opened for write or have had attribute changes (e.g. permissions) and tag them with the identifier "identity" in the audit log file.

**Note:** Reloading the auditd config to set active settings requires the auditd service to be restarted, and may require a system reboot.

## Rationale

Unexpected changes to these files could be an indication that the system has been compromised and that an unauthorized user is attempting to hide their activities or compromise additional accounts.

## Impact

None.

## Audit Procedure

### Command Line

Run the following command to verify the rules are contained in a `.rules` file in the `/etc/audit/rules.d/` directory:

```bash
grep identity /etc/audit/rules.d/*.rules
```

Verify the output matches:

```
-w /etc/group -p wa -k identity
-w /etc/passwd -p wa -k identity
-w /etc/gshadow -p wa -k identity
-w /etc/shadow -p wa -k identity
-w /etc/security/opasswd -p wa -k identity
```

Run the following command to verify that rules are in the running auditd config:

```bash
auditctl -l | grep identity
```

Verify the output matches:

```
-w /etc/group -p wa -k identity
-w /etc/passwd -p wa -k identity
-w /etc/gshadow -p wa -k identity
-w /etc/shadow -p wa -k identity
-w /etc/security/opasswd -p wa -k identity
```

## Expected Result

Output should match the rules listed above.

## Remediation

### Command Line

Edit or create a file in the `/etc/audit/rules.d/` directory ending in `.rules`.

Example: `vi /etc/audit/rules.d/50-identity.rules`

Add the following lines:

```bash
-w /etc/group -p wa -k identity
-w /etc/passwd -p wa -k identity
-w /etc/gshadow -p wa -k identity
-w /etc/shadow -p wa -k identity
-w /etc/security/opasswd -p wa -k identity
```

## Default Value

By default, no audit rules are configured for identity file changes.

## References

1. CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 - Section 4.1.4

## CIS Controls

| Controls Version | Control                                                                                                                                                                                                      |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| v7               | 4.8 Log and Alert on Changes to Administrative Group Membership - Configure systems to issue a log entry and alert when an account is added to or removed from any group assigned administrative privileges. |