CVE 2018-7184
ntpd in ntp 4.2.8p4 before 4.2.8p11 drops bad packets before updating the "received" timestamp, which allows remote attackers to cause a denial of service (disruption) by sending a packet with a zero-origin timestamp causing the association to reset and setting the contents of the packet as the most recent timestamp. This issue is a result of an incomplete fix for CVE-2015-7704.
See the
CVE page on Mitre.org
for more details.