MW WP Form <= 5.1.0 - Unauthenticated Arbitrary File Move via move_temp_file_to_upload_dir

The MW WP Form plugin for WordPress is vulnerable to arbitrary file moving due to insufficient file path validation via the 'generate_user_filepath' function and the 'move_temp_file_to_upload_dir' function in all versions up to, and including, 5.1.0. This makes it possible for unauthenticated attackers to move arbitrary files on the server, which can easily lead to remote code execution when the right file is moved (such as wp-config.php). The vulnerability is only exploitable if a file upload field is added to the form and the “Saving inquiry data in database” option is enabled.