NTP through 4.2.8p12 has a NULL Pointer Dereference.
https://usn.ubuntu.com/4563-1/
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us
https://support.f5.com/csp/article/K61363039
https://security.netapp.com/advisory/ntap-20190503-0001/
https://security.gentoo.org/glsa/201903-15
https://security.FreeBSD.org/advisories/FreeBSD-SA-19:04.ntp.asc
https://seclists.org/bugtraq/2019/May/39
http://support.ntp.org/bin/view/Main/SecurityNotice
http://packetstormsecurity.com/files/152915/FreeBSD-Security-Advisory-FreeBSD-SA-19-04.ntp.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00036.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00032.html