Cis Ubuntu2004 V300 6 2 1 3

---
name: cis-ubuntu2004-v300-6-2-1-3
description: "Ensure journald log file rotation is configured"
category: cis-logging
version: "3.0.0"
author: cyberstrike-official
tags: [cis, ubuntu, linux, ubuntu-20.04, journald]
cis_id: "6.2.1.3"
cis_benchmark: "CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0"
tech_stack: [ubuntu, linux]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# 6.2.1.3 Ensure journald log file rotation is configured (Manual)

## Profile

- Level 1 - Server
- Level 1 - Workstation

## Description

Journald includes the capability of rotating log files regularly to avoid filling up the system with logs or making the logs unmanageably large. The file `/etc/systemd/journald.conf` is the configuration file used to specify how logs generated by Journald should be rotated.

## Rationale

By keeping the log files smaller and more manageable, a system administrator can easily archive these files to another system and spend less time looking through inordinately large log files.

## Audit Procedure

### Command Line

Review the `systemd-journald` configuration. Verify logs are rotated according to site policy. The specific parameters for log rotation are:

Run the following script and review the output to ensure logs are rotated according to site policy:

```bash
#!/usr/bin/env bash
{
    a_output=() a_output2=() l_analyze_cmd="$(readlink -f /bin/systemd-analyze)"
    l_systemd_config_file="systemd/journald.conf"
    a_parameters=("SystemMaxUse=^.+$" "SystemKeepFree=^.+$" "RuntimeMaxUse=^.+$" "RuntimeKeepFree=^.+$"
    "MaxFileSec=^.+$")
    # ... (full audit script from benchmark)
}
```

## Expected Result

Review the output to verify log rotation parameters are configured according to site policy.

## Remediation

### Command Line

Edit `/etc/systemd/journald.conf` or a file ending in `.conf` the `/etc/systemd/journald.conf.d/` directory. Set the following parameters in the `[Journal]` section to ensure logs are rotated according to site policy. The settings should be carefully understood as there are specific edge cases and prioritization of parameters.

Example Configuration:

```ini
[Journal]
SystemMaxUse=1G
SystemKeepFree=500M
RuntimeMaxUse=200M
RuntimeKeepFree=50M
MaxFileSec=1month
```

Example script to create systemd drop-in configuration file:

```bash
{
    a_settings=("SystemMaxUse=1G" "SystemKeepFree=500M" "RuntimeMaxUse=200M" "RuntimeKeepFree=50M"
    "MaxFileSec=1month")
    [ ! -d /etc/systemd/journald.conf.d/ ] && mkdir /etc/systemd/journald.conf.d/
    if grep -Psq -- '^\h*\[Journal\]' /etc/systemd/journald.conf.d/60-journald.conf; then
        printf '%s\n' "" "${a_settings[@]}" >> /etc/systemd/journald.conf.d/60-journald.conf
    else
        printf '%s\n' "" "[Journal]" "${a_settings[@]}" >> /etc/systemd/journald.conf.d/60-journald.conf
    fi
}
```

Note:

- If these settings appear in a canonically later file, or later in the same file, the setting will be overwritten
- Logfile size and configuration to move logfiles to a remote log server should be accounted for when configuring these settings

Run to following command to update the parameters in the service:

```bash
# systemctl reload-or-restart systemd-journald
```

## Default Value

Not specifically configured by default.

## References

1. NIST SP 800-53 Rev. 5: AU-2, AU-7, AU-12

## CIS Controls

| Controls Version | Control                     | IG 1 | IG 2 | IG 3 |
| ---------------- | --------------------------- | ---- | ---- | ---- |
| v8               | 8.2 Collect Audit Logs      |      |      |      |
| v7               | 6.2 Activate audit logging  |      |      |      |
| v7               | 6.3 Enable Detailed Logging |      |      |      |

### MITRE ATT&CK Mappings

| Techniques / Sub-techniques | Tactics | Mitigations |
| --------------------------- | ------- | ----------- |
| T1070, T1070.002            | TA0040  | M1022       |