{
  "id": "CB-UBU-AUDIT-015",
  "standard": "ubuntu",
  "version": "0.1.1",
  "url": "https://baselines.cirsec.org/b/ubuntu/v0.1.1/CB-UBU-AUDIT-015",
  "json": "https://baselines.cirsec.org/b/ubuntu/v0.1.1/CB-UBU-AUDIT-015.json",
  "yaml": "https://baselines.cirsec.org/b/ubuntu/v0.1.1/CB-UBU-AUDIT-015.yml",
  "profiles_effective": [
    "server-hardened"
  ],
  "license": "Text CC BY 4.0, code Apache-2.0",
  "attribution": "CIRSEC Baselines, https://baselines.cirsec.org",
  "control": {
    "id": "CB-UBU-AUDIT-015",
    "title": "Send audit records to a remote server",
    "finding": {
      "title": "Audit records are only stored on the audited system",
      "description": "Someone who gains root on the system can erase or alter the audit log, the only copy of the evidence."
    },
    "status": "active",
    "profiles": [
      "server-hardened"
    ],
    "risk": {
      "severity": "medium"
    },
    "assessment": "automated",
    "tags": [
      "auditd",
      "remote"
    ],
    "description": "The `au-remote` plugin of `audispd-plugins` sends each audit record to a remote `auditd` that\nlistens for them (`tcp_listen_port` on the server). It is turned on with `active = yes` in\n`/etc/audit/plugins.d/au-remote.conf`, and the server is set with `remote_server` in\n`/etc/audit/audisp-remote.conf`.\n",
    "rationale": "A copy kept off the system cannot be erased by an intruder who has taken root, and lets audit\nrecords from many systems be reviewed in one place.\n",
    "impact": "Requires an audit collection server and a network flow to it (TCP 60 by default). Configure\n`network_failure_action` and the queue in `audisp-remote.conf` so an outage does not block the\nsystem.\n",
    "notes": "On Ubuntu 20.04 (auditd 2.8), the plugins are run by `audispd` and their files live in\n`/etc/audisp/`: `/etc/audisp/plugins.d/au-remote.conf` and `/etc/audisp/audisp-remote.conf`.\nFrom 22.04 (auditd 3) they are under `/etc/audit/`.\n\nThe fix is manual: the server address, port and transport (Kerberos or plain TCP inside a\nprotected network) depend on the site. Forwarding audit records through rsyslog with TLS\n(syslog plugin and CB-UBU-AUDIT-009) is an accepted alternative; record it as an exception in\nthe tailoring file.\n",
    "setting": {
      "location": "/etc/audit/plugins.d/au-remote.conf, /etc/audit/audisp-remote.conf (20.04 - /etc/audisp/plugins.d/au-remote.conf, /etc/audisp/audisp-remote.conf)",
      "default_value": "active = no, remote_server empty",
      "recommended_value": "active = yes, remote_server set to the audit collection server"
    },
    "audit": {
      "manual": "1. Run `grep -E '^\\s*active' /etc/audit/plugins.d/au-remote.conf`. It must print `active = yes`.\n2. Run `grep -E '^\\s*remote_server' /etc/audit/audisp-remote.conf`. It must name the server.\nOn Ubuntu 20.04, read the same settings in `/etc/audisp/plugins.d/au-remote.conf` and\n`/etc/audisp/audisp-remote.conf`.\n3. On the server, check that records from this system arrive.\n",
      "checks": [
        {
          "id": "plugin-active",
          "engine": "file-content",
          "description": "The au-remote plugin is active.",
          "versions": [
            "22.04",
            "24.04",
            "26.04"
          ],
          "spec": {
            "path": "/etc/audit/plugins.d/au-remote.conf",
            "pattern": "^\\s*active\\s*=\\s*yes\\s*$"
          }
        },
        {
          "id": "remote-server",
          "engine": "file-content",
          "description": "A remote server is set.",
          "versions": [
            "22.04",
            "24.04",
            "26.04"
          ],
          "spec": {
            "path": "/etc/audit/audisp-remote.conf",
            "pattern": "^\\s*remote_server\\s*=\\s*\\S+"
          }
        },
        {
          "id": "plugin-active-audisp",
          "engine": "file-content",
          "description": "The au-remote plugin is active (auditd 2.8, plugins under /etc/audisp).",
          "versions": [
            "20.04"
          ],
          "spec": {
            "path": "/etc/audisp/plugins.d/au-remote.conf",
            "pattern": "^\\s*active\\s*=\\s*yes\\s*$"
          }
        },
        {
          "id": "remote-server-audisp",
          "engine": "file-content",
          "description": "A remote server is set (auditd 2.8, plugins under /etc/audisp).",
          "versions": [
            "20.04"
          ],
          "spec": {
            "path": "/etc/audisp/audisp-remote.conf",
            "pattern": "^\\s*remote_server\\s*=\\s*\\S+"
          }
        }
      ]
    },
    "remediation": {
      "manual": "1. Set `remote_server = <server>` (and `port`, `transport`) in `/etc/audit/audisp-remote.conf`.\n2. Set `active = yes` in `/etc/audit/plugins.d/au-remote.conf`.\nOn Ubuntu 20.04, edit `/etc/audisp/audisp-remote.conf` and `/etc/audisp/plugins.d/au-remote.conf`.\n3. Run `systemctl restart auditd`, then check on the server that records arrive.\n",
      "rollback": "Set `active = no` in `/etc/audit/plugins.d/au-remote.conf` and restart auditd.\n"
    },
    "references": [
      {
        "title": "audisp-remote.conf(5), Ubuntu manual pages",
        "url": "https://manpages.ubuntu.com/manpages/noble/man5/audisp-remote.conf.5.html",
        "publisher": "Canonical",
        "kind": "vendor-doc",
        "accessed": "2026-10-19"
      },
      {
        "title": "auditd.conf(5), Ubuntu manual pages",
        "url": "https://manpages.ubuntu.com/manpages/noble/man5/auditd.conf.5.html",
        "publisher": "Canonical",
        "kind": "vendor-doc",
        "accessed": "2026-10-19"
      }
    ],
    "mappings": [
      {
        "framework": "anssi-linux",
        "framework_version": "2.0",
        "id": "R73",
        "relation": "related"
      },
      {
        "framework": "nist-800-53r5",
        "framework_version": "5.1.1",
        "id": "AU-4(1)",
        "relation": "equivalent"
      },
      {
        "framework": "nist-800-53r5",
        "framework_version": "5.1.1",
        "id": "AU-9(2)",
        "relation": "related"
      }
    ],
    "threats": [
      {
        "framework": "mitre-attack",
        "id": "T1070.002"
      },
      {
        "framework": "mitre-attack",
        "id": "T1562.012"
      }
    ],
    "related_controls": [
      {
        "id": "CB-UBU-AUDIT-011",
        "type": "requires"
      }
    ],
    "authors": [
      {
        "name": "Alice",
        "github": "Sn0wAlice"
      }
    ],
    "verified": [
      {
        "date": "2026-10-19",
        "by": "Sn0wAlice",
        "versions": [
          "20.04"
        ],
        "environment": "Proxmox VM, Ubuntu 20.04 cloud image, kernel 5.4.0-216-generic",
        "notes": "Fails after auditd install (plugin inactive); passes once active = yes and remote_server are set by hand in /etc/audisp/."
      },
      {
        "date": "2026-10-19",
        "by": "Sn0wAlice",
        "versions": [
          "22.04"
        ],
        "environment": "Proxmox VM, Ubuntu 22.04 cloud image, kernel 5.15.0-198-generic",
        "notes": "Fails after auditd install (plugin inactive), as expected; fix is manual."
      },
      {
        "date": "2026-10-19",
        "by": "Sn0wAlice",
        "versions": [
          "24.04"
        ],
        "environment": "Proxmox VM, Ubuntu 24.04 cloud image, kernel 6.8.0-147-generic",
        "notes": "Fails after auditd install (plugin inactive), as expected; fix is manual."
      },
      {
        "date": "2026-10-19",
        "by": "Sn0wAlice",
        "versions": [
          "26.04"
        ],
        "environment": "Proxmox VM, Ubuntu 26.04 cloud image, kernel 7.0.0-38-generic",
        "notes": "Fails after auditd install (plugin inactive), as expected; fix is manual."
      }
    ],
    "introduced_in": "0.1.0",
    "created": "2026-10-19",
    "updated": "2026-10-19"
  }
}