FreeBSD NSD before 3.2.13 allows remote attackers to crash a NSD child server process (SIGSEGV) and cause a denial of service in the NSD server.
https://www.tenable.com/plugins/nessus/60150
https://vuxml.freebsd.org/freebsd/17f369dc-d7e7-11e1-90a2-000c299b62e1.html