Shared Files < 1.7.70 - Unauthenticated Limited File Upload

Description

The plugins do not perform a capability check in their file-upload handler, which is registered for unauthenticated users and protected only by a nonce that is output on public pages, so an unauthenticated visitor can upload files to a publicly accessible directory and read the server's absolute path from the response. Uploads are limited to WordPress's allowed MIME types, so executable PHP cannot be uploaded.