GD Rating System <= 3.6.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via extra_class Parameter

The GD Rating System plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘extra_class’ parameter in all versions up to, and including, 3.6.1 due to insufficient input sanitization and output escaping. 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.