Divi <= 4.27.6 - Authenticated (Contributor+) Server-Side Request Forgery via 'image_src' Parameter

The Divi theme for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 4.27.6. This is due to the `et_pb_set_video_oembed_thumbnail_resolution()` function using `wp_remote_get()` instead of `wp_safe_remote_get()` to fetch a remote image URL, which does not restrict requests to private or reserved IP ranges. This makes it possible for authenticated attackers, with Contributor-level access and above, to make web requests to arbitrary locations originating from the web application server. The response body is not returned to the attacker (blind SSRF), but two oracles exist: a status oracle (the returned URL string differs depending on whether the target responded with HTTP 200) and a timing oracle (response time varies by target reachability).