ntpq in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (crash) via crafted mode 6 response packets.
http://rhn.redhat.com/errata/RHSA-2016-0780.html
http://rhn.redhat.com/errata/RHSA-2016-2583.html
https://security.gentoo.org/glsa/201607-15
https://security.netapp.com/advisory/ntap-20171004-0001/
http://www.debian.org/security/2015/dsa-3388
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html