CVE-2025-58251

Executive Summary

CVE-2025-58251 is a Missing Authorization vulnerability in the POSIMYTH Sticky Header Effects for Elementor WordPress plugin, affecting versions from n/a through 2.1.2. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized actions within the WordPress ecosystem. The vulnerability has a CVSS score of 4.3 (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.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor for updates from the vendor (POSIMYTH) and apply patches immediately upon release. Since no patch is available, consider disabling the plugin or implementing virtual patching via a Web Application Firewall (WAF).

CVSS Breakdown & Threat Level

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

The threat level is Medium due to the low complexity and no required privileges, but the impact is limited to integrity only.

Deep Dive & Mechanics

The vulnerability stems from a Missing Authorization check (CWE-862) in the plugin's AJAX handlers or REST endpoints. The plugin likely fails to verify user capabilities before executing sensitive actions, such as modifying header settings or saving configuration data. An unauthenticated attacker can send crafted HTTP requests to trigger these actions, potentially altering the site's appearance or injecting malicious content.

The affected component is the sticky-header-effects-for-elementor plugin, which integrates with Elementor page builder. The flaw exists in versions up to and including 2.1.2.

Vulnerable vs. Patched Code

Since no patch is available, a hypothetical vulnerable code snippet might look like:

// Vulnerable: No capability check
add_action('wp_ajax_nopriv_save_header_settings', 'save_header_settings');
function save_header_settings() {
    update_option('sticky_header_settings', $_POST['settings']);
}

A patched version would include:

// Patched: Capability check added
add_action('wp_ajax_save_header_settings', 'save_header_settings');
function save_header_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    update_option('sticky_header_settings', $_POST['settings']);
}

Exploitation & Lab Setup

Red Team

1. Reconnaissance: Identify WordPress sites using the plugin via Shodan dorks or Google dorking.
2. Exploitation: Send a crafted POST request to the vulnerable endpoint:

   POST /wp-admin/admin-ajax.php HTTP/1.1
   Host: target.com
   Content-Type: application/x-www-form-urlencoded
   
   action=save_header_settings&settings[malicious]=value
   

3. Post-Exploitation: Modify header settings to inject JavaScript for XSS or defacement.

Blue Team

1. Detection: Monitor for unusual AJAX requests to admin-ajax.php with action parameters related to the plugin.
2. Honeypot: Deploy a fake endpoint to capture exploitation attempts.
3. Lab Setup: Use a local WordPress instance with the vulnerable plugin installed:

   docker run -d -p 8080:80 --name wp-vuln wordpress:latest
   # Install plugin version 2.1.2 manually
   

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=save_header_settings or similar.
• File: Modified wp_options table entries containing sticky_header_settings.
• Log: WordPress debug logs showing unauthorized AJAX calls.

Detection Engineering

YARA Rule

rule CVE_2025_58251_Sticky_Header_Effects {
    meta:
        description = "Detects exploitation attempts for CVE-2025-58251"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $ajax_action = "save_header_settings"
        $plugin_path = "sticky-header-effects-for-elementor"
    condition:
        $ajax_action or $plugin_path
}

Sigma Rule

title: CVE-2025-58251 - Missing Authorization in Sticky Header Effects
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthorized AJAX requests to the vulnerable plugin
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=save_header_settings'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-58251 - Missing Authorization in Sticky Header Effects"; flow:to_server,established; content:"POST"; http_method; content:"admin-ajax.php"; http_uri; content:"action=save_header_settings"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the plugin until a patch is released.
2. Virtual Patching: Block requests to admin-ajax.php with action=save_header_settings via WAF.
3. Monitoring: Enable detailed logging for AJAX requests and review for anomalies.
4. Update: Apply vendor patch when available (monitor plugin repository).
5. Hardening: Ensure WordPress user roles are properly configured and limit access to admin functions.

Valters IT
Securing Digital Frontiers