WP Time Slots Booking Form <= 1.1.81 - Authenticated (Admin+) Stored Cross Site Scripting

The WP Time Slots Booking Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in versions up to, and including, 1.1.81 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrative-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.