Snazzy Social Media Feed <= 2.5 - Unauthenticated Arbitrary File Upload via 'pluginURL' Parameter

The Snazzy Social Media Feed plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.5 via the (file scope) function. This is due to missing WordPress bootstrap, authentication, capability, and nonce checks in the standalone save-to-cache.php script, combined with insufficient sanitization of the pluginURL parameter before it is written to a web-executable PHP file. This makes it possible for authenticated attackers, with subscriber-level access and above, to upload files that may be executable, which makes remote code execution possible. The save-to-cache.php script is directly reachable without loading WordPress; FILTER_SANITIZE_URL — the only filter applied to the pluginURL value — preserves the characters required to craft a valid PHP payload, which is then written verbatim into cached-content/cached-feed.php and immediately executable via a single GET request.