Church Admin <= 5.0.28 - Authenticated (Administrator+) Blind Server-Side Request Forgery via 'audio_url' Parameter

The Church Admin plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 5.0.28 due to insufficient validation of user-supplied URLs in the 'audio_url' parameter. This makes it possible for authenticated attackers, with Administrator-level access, to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.