The Avatar plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in a function in all versions up to, and including, 0.1.4. 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).
https://wordpress.org/plugins/avatar/
https://plugins.trac.wordpress.org/browser/avatar/trunk/avatar.php#L417