Unauthenticated Shortcode Execution Vulnerability in Special Text Boxes Plugin

Summary

The The Special Text Boxes plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 6.2.2. This is due to the plugin adding the filter add_filter('comment_text', 'do_shortcode'); which will run all shortcodes in comments. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.