Folders < 2.9.3 - Authenticated (Author+) Arbitrary File Upload in handle_folders_file_upload

Description

The Folders plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the handle_folders_file_upload function in versions up to, and including, 2.9.2. This makes it possible for authenticated attackers, with author-level permissions or above, to upload arbitrary files on the affected site's server which may make remote code execution possible.