nsd -- Denial of Service

Tom Hendrikx reports:

It is possible to crash (SIGSEGV) a NSD child server process by
sending it a DNS packet from any host on the internet and the per
zone stats build option is enabled. A crashed child process will
automatically be restarted by the parent process, but an attacker
may keep the NSD server occupied restarting child processes by
sending it a stream of such packets effectively preventing the
NSD server to serve.