View at Official ubuntu advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2016-4955 low priority: Ubuntu including 1 source packages (ntp), 7 status rows across 7 suites (precise, trusty, upstream, wily, xenial, yakkety, zesty): released 3, not-affected 2, ignored 1, needs-triage 1.
ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.