pwncat_pwnkit

Introduction

The purpose of this module is to attempt to exploit CVE-2021-4034 (pwnkit) on a target when using pwncat.

There is no need to setup any directories, compile any source or even have gcc on the remote target; the pwnkit module takes care of this automatically using the pwncat framework.

Setup and Use

• Simply copy pwnkit.py somewhere on your host where pwncat-cs is installed. ie: /home/user/pwncat_mods
• In pwncat, simply type: load /home/user/pwncat_mods
• To confirm the module loaded, type: search pwnkit. You should see something like this:

(local) pwncat$ search pwnkit
                                                      Results                                                      
                   ╷                                                                                               
  Name             │ Description                                                                                   
 ══════════════════╪══════════════════════════════════════════════════════════════════════════════════════════════ 
  pwnkit           │ Exploit CVE-2021-4034 to privesc to root

• To execute, simply type run pwnkit. If it's successful, you should see the UID change to 0, and now be root. ie:

(local) pwncat$ run pwnkit
[00:12:15] 10.10.184.131:47148: ran pwnkit. UID : Before(1000) | After(0)                            manager.py:955
           Module pwnkit completed successfully                                                          run.py:100
(local) pwncat$                                                                                                    
(remote) root@pwnkit:/# id
uid=0(root) gid=0(root) groups=0(root),1000(tryhackme)

Tips

• If you don't want to always call load, you can have pwncat automatically load this module on startup by placing it in ~/.local/share/pwncat/modules
• To use the cross-compiler to build the exploit on your machine and upload it to the target, you need to set the cross variable in your pwncatrc file. This file is typically found at ~/.local/share/pwncat/pwncatrc`. ie:

# Set the gcc path
set cross "/usr/bin/gcc"

Thanks

A special shout out to Caleb Stewart for being helpful as I pushed through learning the pwncat framework from a dev perspective. I will get a pull request to put this in the main pwncat escalate module someday when I have free time... I promise. :-)