Abandoned Cart Pro for WooCommerce <= 9.16.0 - Authenticated (Subscriber+) Arbitrary File Upload

The Abandoned Cart Pro for WooCommerce plugin contains an authenticated arbitrary file upload vulnerability due to missing file type validation in the wcap_add_to_cart_popup_upload_files function in all versions up to, and including, 9.16.0. This makes it possible for an authenticated attacker, with subscriber-level access and above, to upload arbitrary files on the affected site's server which may allow for either remote or local code execution depending on the server configuration.