http://support.ntp.org/bin/view/Main/NtpBug3361 An exploitable denial of service vulnerability exists in the origin timestamp check functionality of ntpd 4.2.8p9. A specially crafted unauthenticated network packet can be used to reset the expected origin timestamp for target peers. Legitimate replies from targeted peers will fail the origin timestamp check (TEST2) causing the reply to be dropped and creating a denial of service condition. This vulnerability can only be exploited if the attacker can spoof all of the servers. Affects: ntp-4.2.8p9 (21 Nov 2016), up to but not including ntp-4.2.8p10 https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9042