THIS PRESS RELEASE about the FileMaker Server update is a bit sparse on information. It evidently addresses a ‘security issue’ of unknown provenance. Nevertheless, it’s probably appropriate to install it on both Mac and Windows servers.
This software updates version 13.0v3 of FileMaker Server to version 13.0v4. For instructions on running the updater, see “Updater Instructions” below.
Updates in FileMaker Server 13.0v4