WP Dropzone <= 1.1.0 - Authenticated (Subscriber+) Arbitrary File Upload

The WP Dropzone plugin for WordPress is vulnerable to authenticated arbitrary file upload in all versions up to, and including, 1.1.0 via the `ajax_upload_handle` function. This is due to the chunked upload functionality writing files directly to the uploads directory before any file type validation occurs. This makes it possible for authenticated attackers, with subscriber level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible.