CVE-2025-66069

Executive Summary

CVE-2025-66069 is a Missing Authorization vulnerability in the PPOM for WooCommerce plugin (slug: woocommerce-product-addon) developed by Themeisle. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data exposure or manipulation of product add-on fields. The vulnerability affects all versions up to and including 33.0.16. As a WordPress plugin, this issue resides entirely within the WordPress ecosystem and is not related to the underlying web server (Apache/Nginx).

The CVSS score of 4.3 (Medium) reflects a low complexity, network-based attack with no privileges required, but the impact is limited to confidentiality. No public proof-of-concept (PoC) or exploit code has been released, and the EPSS score is 0.0%, indicating a low probability of exploitation in the wild. However, the lack of a patch from the vendor makes this a significant risk for sites using the plugin.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress Plugin Directory. As a supply chain risk, any site that has installed or updated the PPOM for WooCommerce plugin to version 33.0.16 or earlier is potentially affected. Administrators should monitor the plugin’s update channel for a patched version and consider temporary disabling or replacing the plugin if no patch is forthcoming.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The vulnerability can be exploited remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action is required.
• Scope (S): Unchanged (U) – The exploit does not affect other components.
• Confidentiality (C): Low (L) – Limited information disclosure.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Threat Level: Medium. The low EPSS score and absence of public exploits reduce immediate risk, but the missing authorization could allow attackers to view sensitive product configurations or metadata.

Deep Dive & Mechanics

The PPOM for WooCommerce plugin allows store owners to add custom fields (e.g., text inputs, file uploads, dropdowns) to WooCommerce products. The vulnerability lies in the plugin’s AJAX handlers or REST endpoints that process requests for product add-on data. Specifically, the plugin fails to properly verify user capabilities (e.g., manage_options or edit_products) before exposing or modifying add-on field configurations.

An unauthenticated attacker can craft a direct HTTP request to a vulnerable endpoint (e.g., /wp-admin/admin-ajax.php?action=ppom_get_fields) without a valid nonce or capability check. This can lead to:

• Disclosure of all custom field definitions (including field names, types, and default values).
• Potential modification of field settings if write endpoints are also unprotected.

The root cause is a missing call to current_user_can() or wp_verify_nonce() in the plugin’s AJAX callback functions.

Vulnerable vs. Patched Code

Vulnerable Code (<= 33.0.16):

add_action('wp_ajax_ppom_get_fields', 'ppom_get_fields_callback');
add_action('wp_ajax_nopriv_ppom_get_fields', 'ppom_get_fields_callback');

function ppom_get_fields_callback() {
    // No capability check
    $product_id = intval($_GET['product_id']);
    $fields = get_post_meta($product_id, '_ppom_fields', true);
    wp_send_json_success($fields);
}

Patched Code (Hypothetical):

add_action('wp_ajax_ppom_get_fields', 'ppom_get_fields_callback');
// Remove nopriv hook to require authentication

function ppom_get_fields_callback() {
    // Add capability check
    if (!current_user_can('edit_products')) {
        wp_send_json_error('Unauthorized', 403);
        return;
    }
    $product_id = intval($_GET['product_id']);
    $fields = get_post_meta($product_id, '_ppom_fields', true);
    wp_send_json_success($fields);
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• A WordPress site with PPOM for WooCommerce <= 33.0.16 installed and activated.
• A WooCommerce product with custom fields defined via PPOM.

Exploitation Steps:

1. Identify the vulnerable AJAX endpoint: http://target/wp-admin/admin-ajax.php?action=ppom_get_fields&product_id=1
2. Send a GET request without any authentication:

   curl -v "http://target/wp-admin/admin-ajax.php?action=ppom_get_fields&product_id=1"
   

3. If successful, the response will contain JSON with the product’s custom field definitions.

Note: No public exploit code exists; this is a manual exploitation scenario.

Blue Team

Detection:

• Monitor for requests to /wp-admin/admin-ajax.php with action=ppom_get_fields from unauthenticated users.
• Look for anomalous spikes in AJAX requests targeting PPOM endpoints.

Hunting:

• Search web server logs for patterns like admin-ajax.php?action=ppom_ and correlate with IP addresses that have no prior authenticated sessions.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to /wp-admin/admin-ajax.php with parameter action=ppom_get_fields or action=ppom_save_fields from unauthenticated sources.
  • Repeated attempts to enumerate product IDs via the product_id parameter.

• File IOCs:

  • Modified or unexpected entries in the wp_postmeta table for _ppom_fields meta key.
  • Unauthorized changes to plugin files in /wp-content/plugins/woocommerce-product-addon/.

• Log IOCs:

  • Web server logs showing 200 responses to admin-ajax.php without a valid cookie or nonce header.

Detection Engineering

YARA Rule

rule CVE_2025_66069_PPOM_Missing_Auth {
    meta:
        description = "Detects exploitation attempts of CVE-2025-66069 in PPOM for WooCommerce"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-66069"
    strings:
        $ajax_action = "action=ppom_get_fields"
        $ajax_action2 = "action=ppom_save_fields"
        $product_param = "product_id="
    condition:
        any of ($ajax_action, $ajax_action2) and $product_param
}

Sigma Rule

title: CVE-2025-66069 PPOM Missing Authorization Exploitation
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated requests to PPOM AJAX endpoints
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-uri-query|contains:
            - 'action=ppom_get_fields'
            - 'action=ppom_save_fields'
        sc-status: 200
    filter:
        cs(Cookie)|contains: 'wordpress_logged_in'
    condition: selection and not filter
falsepositives:
    - Legitimate admin requests (rare)
level: high

Suricata Rule

alert http any any -> $EXTERNAL_NET any (msg:"CVE-2025-66069 PPOM Missing Authorization Attempt"; flow:to_server,established; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=ppom_get_fields"; http_uri; content:"product_id="; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if it is not critical to business operations until a patch is released.
2. Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to admin-ajax.php with action=ppom_* parameters.
3. Restrict access to /wp-admin/admin-ajax.php via .htaccess for non-logged-in users:

   RewriteCond %{REQUEST_URI} ^/wp-admin/admin-ajax\.php$
   RewriteCond %{HTTP_COOKIE} !wordpress_logged_in
   RewriteRule ^ - [F]
   

Long-Term Fix:

• Apply the vendor patch once released (currently UNKNOWN).
• If the plugin is abandoned, consider migrating to an alternative product add-on plugin with active security support.

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