The ntpq protocol in NTP before 4.2.8p7 allows remote attackers to conduct replay attacks by sniffing the network.
https://www.kb.cert.org/vuls/id/718152
https://security.netapp.com/advisory/ntap-20200204-0003/
https://security.gentoo.org/glsa/201607-15
https://security.FreeBSD.org/advisories/FreeBSD-SA-16:09.ntp.asc
https://bto.bluecoat.com/security-advisory/sa113
http://www.securitytracker.com/id/1034782
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160127-ntpd
http://support.ntp.org/bin/view/Main/NtpBug2947
http://lists.opensuse.org/opensuse-updates/2016-05/msg00114.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00048.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00038.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00020.html
http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00060.html
http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00059.html