Stream <= 4.0.2 - Authenticated (Admin+) Server-Side Request Forgery

The Stream plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 4.0.2 due to insufficient validation on the webhook feature. This makes it possible for authenticated attackers, with administrator-level access and above, to make web requests to arbitrary locations originating from the web application which can be used to query and modify information from internal services.