Unrestricted Upload of File with Dangerous Type
The WooCommerce Help Scout WordPress plugin before 2.9.1 (https://woocommerce.com/products/woocommerce-help-scout/) allows unauthenticated users to upload any files to the site which by default will end up in wp-content/uploads/hstmp.
CWE-434 - Unrestricted Upload of File with dangerous type
'Unrestricted file upload with dangerous type' attacks involve an attacker uploading or transferring files of dangerous types to the server. The severity of such an attack depends upon the execution mechanism and the storage location of the uploaded file. Thus, it may range from simple defacement to arbitrary file execution, and complete system takeover.