iubenda | All-in-one Compliance for GDPR / CCPA Cookie Consent + more <= 3.13.4 - Unauthenticated Stored Cross-Site Scripting via Comment Content

The iubenda | All-in-one Compliance for GDPR / CCPA Cookie Consent + more plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 3.13.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit works by embedding KSES-allowed markup such as abbr title attributes and HTML comments in a submitted comment so that the global strtr() substitution strips substrings from an inert tag, mutating it into an executable element such as an img onerror handler that runs in the WordPress origin for any visitor, including logged-in administrators.