Unhandled exception on illegal filename_disk value

Directus is a free and open-source data platform for headless content management. The Directus process can be aborted by having an authorized user update the `filename_disk` value to a folder and accessing that file through the `/assets` endpoint. This vulnerability has been patched and release v9.15.0 contains the fix. Users are advised to upgrade. Users unable to upgrade may prevent this problem by making sure no (untrusted) non-admin users have permissions to update the `filename_disk` field on `directus_files`.