Widgets for Google Reviews <= 13.2.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via trustindex Shortcode

The Widgets for Google Reviews plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's `trustindex` shortcode in all versions up to, and including, 13.2.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.