Youzify <= 1.3.6 - Authenticated (Subscriber+) Stored Cross-Site Scripting via 'checkin_place_id' Parameter

The Youzify plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'checkin_place_id' parameter in all versions up to, and including, 1.3.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.