In NetworkServerControlImpl.checkShutdownPrivileges() code fetches the internal authentication service to perform user authentication.
However if no such authentication service is found (null is returned) then authentication is bypassed, this has the potential of being a security hole.
The discussion in DERBY-2109 indicated that even with authentication NONE, there is still an internal authentication service, thus null is not a valid return when getting the internal authentication service. A secure fail safe system would be to not bypass authentication if null is returned.
I tried removing the check for null in the method and that lead to NullPointerExceptions. This means that something wrong is going on and very possibly no authentication checks are actually being made when shutting down the network server.
The null return might be due to checking the authentication after Derby has been shutdown.