Google Tag Manager for WordPress Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Google Tag Manager for WordPress (GTM4WP) plugin, affecting versions through 1.15.1. The issue arises from insufficient escaping of the 'gtm4wp-options[scroller-contentid]' parameter in the 'frontend.php' file. This vulnerability allows attackers with administrative access to inject arbitrary web scripts. It is particularly concerning for multi-site installations where 'unfiltered_html' is disabled for administrators, as well as for sites with 'unfiltered_html' restrictions.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the affected page.

Remediation

Users are advised to update the Google Tag Manager for WordPress plugin to version 1.15.2 or newer.