Engelsystem is a shift planning system for chaos events. A Blind SSRF in the "Import schedule" functionality makes it possible to perform a port scan against the local environment. This vulnerability has been fixed in commit ee7d30b33. If a patch cannot be deployed, operators should ensure that no HTTP(s) services listen on localhost and/or systems only reachable from the host running the engelsystem software. If such services are necessary, they should utilize additional authentication.