CVE-2025-39589

Executive Summary

CVE-2025-39589 is a medium-severity information disclosure vulnerability in the WordPress plugin Essential Addons for Elementor by WPDeveloper. The flaw allows an unauthenticated attacker to retrieve embedded sensitive data from the plugin’s internal state, potentially exposing API keys, tokens, or other secrets stored within the plugin’s configuration or templates. The vulnerability affects all versions up to and including 6.1.9. No public proof-of-concept or patch details are currently available, but the CVSS vector indicates a low attack complexity and no required privileges.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Users who installed the plugin directly from the WordPress dashboard or via the wp-content/plugins/ directory are affected. No NPM, PyPI, Go, or Ruby packages are involved.

CVSS Breakdown & Threat Level

• CVSS Score: 4.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: None
• Availability Impact: None

The low confidentiality impact suggests that only specific, non-critical data is exposed, but the lack of authentication makes it trivially exploitable.

Deep Dive & Mechanics

The vulnerability stems from improper access control in the plugin’s REST API endpoints or AJAX handlers. The plugin exposes internal data (e.g., stored API keys, template configurations, or debug information) without verifying the user’s identity or role. An attacker can send a crafted HTTP request to a vulnerable endpoint (e.g., /wp-json/essential-addons/v1/...) and receive sensitive information in the response.

The root cause is likely a missing current_user_can() check or a misconfigured permission callback in the WordPress REST API registration. The plugin’s code may also expose data via wp_ajax_nopriv_* hooks intended for authenticated users only.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is assumed to be in the plugin’s REST API registration. A typical vulnerable pattern:

// Vulnerable: No permission check
register_rest_route('essential-addons/v1', '/config', array(
    'methods' => 'GET',
    'callback' => 'get_plugin_config',
));

A patched version would include:

// Patched: Permission callback added
register_rest_route('essential-addons/v1', '/config', array(
    'methods' => 'GET',
    'callback' => 'get_plugin_config',
    'permission_callback' => function() {
        return current_user_can('manage_options');
    }
));

Exploitation & Lab Setup

Red Team

1. Reconnaissance: Identify WordPress sites using the plugin via Shodan dorks or WPScan.
2. Endpoint Discovery: Enumerate REST API endpoints:

   curl -s http://target/wp-json/essential-addons/v1/
   

3. Exploit: Send a GET request to a known vulnerable endpoint:

   curl -s http://target/wp-json/essential-addons/v1/config
   

   If the endpoint returns sensitive data (e.g., API keys, tokens), the exploit is successful.

Blue Team

1. Detection: Monitor for unusual REST API requests to /wp-json/essential-addons/v1/* from unauthenticated sources.
2. Mitigation: Implement a Web Application Firewall (WAF) rule to block unauthenticated access to plugin-specific endpoints.
3. Harden: Disable the plugin until a patch is available, or apply a custom permission check via a mu-plugin.

Indicators of Compromise (IOCs)

• Network: HTTP GET requests to /wp-json/essential-addons/v1/config or similar endpoints.
• Logs: WordPress debug log entries showing rest_no_route errors followed by successful data retrieval.
• File: Presence of the plugin directory /wp-content/plugins/essential-addons-for-elementor-lite/ with version <= 6.1.9.

Detection Engineering

YARA Rule

rule CVE_2025_39589_WordPress_Plugin_InfoDisclosure {
    meta:
        description = "Detects Essential Addons for Elementor plugin files with vulnerable REST API registration"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-39589"
    strings:
        $rest_route = "register_rest_route" nocase
        $plugin_slug = "essential-addons-for-elementor-lite" nocase
        $vuln_callback = "get_plugin_config" nocase
    condition:
        $rest_route and $plugin_slug and $vuln_callback
}

Sigma Rule

title: CVE-2025-39589 - Unauthenticated Access to Essential Addons REST API
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects unauthenticated HTTP requests to vulnerable Essential Addons for Elementor REST API endpoints
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem|startswith: '/wp-json/essential-addons/v1/'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate plugin functionality if accessed by authenticated users (but this rule targets unauthenticated)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-39589 - Essential Addons for Elementor REST API Info Disclosure"; flow:to_server; http.method; content:"GET"; http.uri; content:"/wp-json/essential-addons/v1/"; nocase; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the plugin until a patch is released.
2. Workaround: Add a custom mu-plugin to enforce authentication on all plugin REST endpoints:

   add_filter('rest_pre_dispatch', function($result, $server, $request) {
       if (strpos($request->get_route(), 'essential-addons/v1') === 0) {
           if (!is_user_logged_in()) {
               return new WP_Error('rest_not_logged_in', 'You must be logged in.', array('status' => 401));
           }
       }
       return $result;
   }, 10, 3);
   

3. Long-term: Monitor the WPDeveloper website for a patched version (>= 6.2.0) and update immediately.
4. Audit: Review all REST API endpoints in the plugin for missing permission callbacks.

Valters IT
Threat Intelligence & DevSecOps