WordPress User Extra Fields <= 16.7 - Authenticated (Subscriber+) Arbitrary File Deletion via save_fields Function

The WordPress User Extra Fields plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the save_fields() function in all versions up to, and including, 16.7. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php).