Seraphinite Accelerator <= 2.20.52 - Authenticated (Subscriber+) Server-Side Request Forgery in OnAdminApi_HtmlCheck

The Seraphinite Accelerator plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 2.20.52 via the OnAdminApi_HtmlCheck function. This makes it possible for authenticated attackers, with subscriber-level access and above, to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.