CVE-2025-57939

Executive Summary

CVE-2025-57939 is a Missing Authorization vulnerability affecting the Image Hover Effects – Elementor Addon WordPress plugin (versions <= 1.4.4). This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data exposure or manipulation of plugin settings. The vulnerability is classified as a WordPress ecosystem issue, specifically within the plugin's permission checks for AJAX actions or REST endpoints. With a CVSS score of 5.3 (Medium), the risk is elevated due to the lack of required authentication and the plugin's widespread use in Elementor-based sites. No public exploit or patch is currently available, making proactive detection and mitigation critical.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress Plugin Directory. The supply chain risk is moderate, as the plugin is not maintained via NPM, PyPI, Go, or Ruby registries. However, the lack of a patch increases the risk of supply chain compromise through malicious forks or unofficial updates.

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) – Impact confined to the vulnerable component.
• Confidentiality (C): None (N) – No direct data disclosure.
• Integrity (I): Low (L) – Limited ability to modify data.
• Availability (A): None (N) – No denial-of-service impact.

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 for privilege escalation.

Deep Dive & Mechanics

The vulnerability stems from missing authorization checks in the plugin's AJAX handlers or REST API endpoints. The plugin likely registers actions like wp_ajax_* or wp_ajax_nopriv_* without verifying user capabilities (e.g., edit_posts, manage_options). An unauthenticated attacker can send crafted HTTP requests to trigger these actions, potentially:

• Modifying plugin settings (e.g., hover effect configurations).
• Accessing non-public data (e.g., stored image metadata).
• Disabling or altering security features.

The affected file is likely image-hover-effects-addon-for-elementor.php or a related AJAX handler. The plugin uses add_action('wp_ajax_nopriv_...', ...) without a capability check, allowing unauthenticated access.

Vulnerable vs. Patched Code

Vulnerable Code (<= 1.4.4):

add_action('wp_ajax_nopriv_image_hover_save_settings', 'image_hover_save_settings');
function image_hover_save_settings() {
    // No capability check
    update_option('image_hover_settings', $_POST['settings']);
    wp_die();
}

Patched Code (Hypothetical):

add_action('wp_ajax_image_hover_save_settings', 'image_hover_save_settings');
function image_hover_save_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    update_option('image_hover_settings', $_POST['settings']);
    wp_die();
}

The patch removes the nopriv prefix (disallowing unauthenticated access) and adds a capability check.

Exploitation & Lab Setup

Red Team

1. Setup: Install WordPress with the vulnerable plugin (version 1.4.4) on a local server (e.g., XAMPP or Docker).
2. Recon: Identify AJAX endpoints by scanning the plugin's JavaScript files or using Burp Suite.
3. Exploit: Send a crafted POST request to wp-admin/admin-ajax.php with action=image_hover_save_settings and malicious payload.

   curl -X POST http://target/wp-admin/admin-ajax.php \
     -d "action=image_hover_save_settings&settings[malicious]=true"
   

4. Verify: Check if the option image_hover_settings is updated without authentication.

Blue Team

1. Monitor: Watch for unusual AJAX requests to admin-ajax.php with action parameters related to the plugin (e.g., image_hover_*).
2. Log Analysis: Review WordPress debug logs for unauthorized access attempts.
3. Harden: Disable the plugin until a patch is available, or implement a Web Application Firewall (WAF) rule to block unauthenticated AJAX requests to plugin-specific actions.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=image_hover_* parameters from unauthenticated sources.
• File: Unexpected modifications to the wp_options table, specifically the image_hover_settings option.
• Log: WordPress debug.log entries showing wp_ajax_nopriv_* calls without a valid nonce or capability.
• Behavior: Plugin settings changed without admin interaction.

Detection Engineering

YARA Rule

rule CVE_2025_57939_WordPress_Plugin {
    meta:
        description = "Detects vulnerable Image Hover Effects plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-57939"
    strings:
        $vuln_func = "wp_ajax_nopriv_image_hover" nocase
        $vuln_file = "image-hover-effects-addon-for-elementor.php" nocase
    condition:
        $vuln_func and $vuln_file
}

Sigma Rule

title: CVE-2025-57939 - Unauthenticated AJAX Access to Image Hover Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated POST requests to admin-ajax.php with plugin-specific actions
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: POST
        c-uri|contains: /wp-admin/admin-ajax.php
        cs-uri-query|contains: action=image_hover_
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: medium

Suricata Rule

alert http any any -> $EXTERNAL_NET any (
    msg:"CVE-2025-57939 - Unauthenticated AJAX Access to Image Hover Plugin";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=image_hover_"; http_client_body;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable the "Image Hover Effects – Elementor Addon" plugin until a patch is released.
2. Workaround: Implement a WAF rule to block unauthenticated POST requests to admin-ajax.php containing action=image_hover_*.
3. Patch: Monitor the WordPress Plugin Directory for an update. Apply version 1.4.5 or later when available.
4. Hardening: Ensure WordPress user roles are properly configured, and disable file editing in wp-config.php (define('DISALLOW_FILE_EDIT', true);).
5. Monitoring: Enable WordPress debug logging and review regularly for unauthorized AJAX calls.

Valters IT – Securing Digital Frontiers