CVE-2025-66153

Executive Summary

CVE-2025-66153 is a Missing Authorization vulnerability in the Headinger for Elementor WordPress plugin (versions <= 1.1.4). This flaw allows unauthenticated attackers to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or modification. The vulnerability resides in the plugin's REST API or AJAX handlers, which fail to properly verify user capabilities before executing privileged actions. As a WordPress plugin, this issue is specific to the WordPress ecosystem and does not involve server-level software like Apache or Nginx.

The CVSS score of 5.4 (Medium) reflects the low attack complexity and network-based vector, but the lack of required privileges makes it a viable target for automated scanning. No public proof-of-concept (PoC) or exploit code has been released, and the vendor has not provided a patch. The EPSS score of 0.0% indicates low current exploitation activity, but this may change as the vulnerability becomes more widely known.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository and third-party marketplaces. Users who installed the plugin from untrusted sources may be at higher risk. The plugin's update mechanism does not enforce authentication for critical functions, making it a supply chain risk for sites relying on this component.

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) – Vulnerability does not affect other components.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited data modification.
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. The vulnerability is easy to exploit but has limited impact. However, in a WordPress context, it could be chained with other flaws to escalate privileges or access sensitive configuration data.

Deep Dive & Mechanics

The Headinger for Elementor plugin adds custom heading styles and dynamic content features to Elementor page builder. The vulnerability stems from missing authorization checks in the plugin's REST API endpoints or AJAX actions that handle settings, template imports, or user data.

Root Cause: The plugin uses wp_ajax_* hooks or register_rest_route() without verifying the current_user_can() capability. For example, an endpoint like /wp-json/headinger/v1/settings may allow any unauthenticated user to read or modify plugin options.

Attack Flow:

1. Attacker identifies the vulnerable endpoint via directory enumeration or plugin fingerprinting.
2. Sends a crafted HTTP request (GET or POST) to the endpoint without any authentication token.
3. The server processes the request and returns sensitive data (e.g., API keys, user lists) or performs unauthorized actions (e.g., updating plugin settings).

Technical Details:

• The plugin likely uses register_rest_route() with permission_callback set to __return_true or missing entirely.
• Alternatively, AJAX handlers may use wp_ajax_nopriv_* hooks that bypass capability checks.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common WordPress security practices.

Vulnerable Code (hypothetical):

add_action('rest_api_init', function () {
    register_rest_route('headinger/v1', '/settings', array(
        'methods' => 'GET',
        'callback' => 'headinger_get_settings',
        'permission_callback' => '__return_true' // Missing authorization
    ));
});

function headinger_get_settings() {
    return get_option('headinger_settings');
}

Patched Code (hypothetical):

add_action('rest_api_init', function () {
    register_rest_route('headinger/v1', '/settings', array(
        'methods' => 'GET',
        'callback' => 'headinger_get_settings',
        'permission_callback' => function () {
            return current_user_can('manage_options'); // Proper authorization
        }
    ));
});

function headinger_get_settings() {
    if (!current_user_can('manage_options')) {
        return new WP_Error('rest_forbidden', 'Unauthorized', array('status' => 403));
    }
    return get_option('headinger_settings');
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with Headinger for Elementor <= 1.1.4 installed and active.
• Network access to the site.

Exploitation Steps:

1. Identify Vulnerable Endpoint:

   curl -s -X GET "http://target.com/wp-json/headinger/v1/settings" | jq .
   

   If the response returns plugin settings without authentication, the endpoint is vulnerable.

2. Extract Sensitive Data:

   curl -s -X GET "http://target.com/wp-json/headinger/v1/users" | jq '.data'
   

3. Modify Plugin Settings:

   curl -s -X POST "http://target.com/wp-json/headinger/v1/settings" \
     -H "Content-Type: application/json" \
     -d '{"option_name": "new_value"}'
   

Lab Setup:

• Use a local WordPress instance (e.g., via Docker) with the vulnerable plugin version.
• Install and activate the plugin, then test endpoints with curl or Postman.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual REST API requests to /wp-json/headinger/v1/* from unauthenticated sources.
• Look for HTTP 200 responses to endpoints that should require authentication.

Defense:

• Immediately disable the plugin if no patch is available.
• Implement a Web Application Firewall (WAF) rule to block requests to /wp-json/headinger/v1/* from non-admin IPs.
• Use a WordPress security plugin (e.g., Wordfence) to add virtual patching.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests to /wp-json/headinger/v1/settings or similar endpoints without authentication headers.
• Repeated 403 errors followed by 200 success on the same endpoint (indicating bypass attempts).

File IOCs:

• Modified wp-content/plugins/headinger-elementor/ files (check file integrity).
• Unexpected entries in wp_options table (e.g., headinger_settings with altered values).

Log IOCs:

• WordPress debug log entries showing rest_forbidden errors followed by successful access.
• Apache/Nginx access logs with POST /wp-json/headinger/v1/ from unknown IPs.

Detection Engineering

YARA Rule

rule CVE_2025_66153_Headinger_Missing_Auth {
    meta:
        description = "Detects vulnerable Headinger for Elementor plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-66153"
    strings:
        $vuln_func1 = "permission_callback" ascii wide nocase
        $vuln_func2 = "__return_true" ascii wide nocase
        $vuln_func3 = "wp_ajax_nopriv_" ascii wide nocase
        $plugin_id = "headinger-elementor" ascii wide nocase
    condition:
        $plugin_id and ($vuln_func1 or $vuln_func2 or $vuln_func3)
}

Sigma Rule

title: CVE-2025-66153 - Missing Authorization in Headinger for Elementor
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated access to Headinger plugin REST endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem|startswith: '/wp-json/headinger/v1/'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin requests from authenticated users (filter by cookie)
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-66153 - Headinger for Elementor Missing Authorization Attempt";
    flow:to_server,established;
    content:"/wp-json/headinger/v1/"; http_uri;
    pcre:"/^GET \/wp-json\/headinger\/v1\//i";
    classtype:attempted-recon;
    sid:10000001;
    rev:1;
    reference:cve,2025-66153;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Add WAF rules to block unauthenticated requests to /wp-json/headinger/v1/*.
3. Audit user accounts for any unauthorized changes made via the vulnerability.

Long-Term Fix:

• Monitor the plugin's official page for updates.
• If the vendor does not respond, consider forking the plugin and adding proper authorization checks (e.g., current_user_can('manage_options')).
• Replace the plugin with an alternative that has active security maintenance.

Workaround:

• Use a WordPress security plugin to add virtual patching (e.g., NinjaFirewall, Wordfence).
• Restrict access to REST API endpoints via .htaccess:

  RewriteEngine On
  RewriteCond %{REQUEST_URI} ^/wp-json/headinger/v1/ [NC]
  RewriteCond %{HTTP_COOKIE} !wordpress_logged_in [NC]
  RewriteRule ^ - [F,L]
  

Valters IT
DevSecOps & Cyber Threat Intelligence