Fluent Support < 2.3.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'redirect-to' Shortcode Attribute

Description

The Fluent Support – Helpdesk & Customer Support Ticket System plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'redirect-to' Shortcode Attribute in all versions up to, and including, 2.3.0 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. The XSS payload is in a hidden attribute so it only fires in specific browsers when specific access keys are used making exploitation unlikely.