Product Input Fields for WooCommerce <= 1.9 - Authenticated (Contributor+) Arbitrary File Read

The Product Input Fields for WooCommerce plugin for WordPress is vulnerable to Directory Traversal in all versions up to, and including, 1.9 via the handle_downloads() function due to insufficient file path validation/sanitization. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the contents of arbitrary files on the server, which can contain sensitive information.