NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to bypass the origin timestamp validation via a packet with an origin timestamp set to zero.
https://www.kb.cert.org/vuls/id/718152
https://www.arista.com/en/support/advisories-notices/security-advisories/1332-security-advisory-19
https://us-cert.cisa.gov/ics/advisories/icsa-21-103-11
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161123-ntpd
https://security.netapp.com/advisory/ntap-20171031-0001/
https://security.netapp.com/advisory/ntap-20171004-0002/
https://security.gentoo.org/glsa/201607-15
https://security.FreeBSD.org/advisories/FreeBSD-SA-16:09.ntp.asc
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03766en_us
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03750en_us
https://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf
https://bto.bluecoat.com/security-advisory/sa113
http://www.ubuntu.com/usn/USN-3096-1
http://www.securitytracker.com/id/1034782
http://www.securityfocus.com/bid/81811
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.debian.org/security/2016/dsa-3629
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160428-ntpd
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160127-ntpd
http://support.ntp.org/bin/view/Main/SecurityNotice#April_2016_NTP_4_2_8p7_Security
http://rhn.redhat.com/errata/RHSA-2016-0063.html
http://lists.opensuse.org/opensuse-updates/2016-05/msg00114.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.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
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/176434.html
http://lists.fedoraproject.org/pipermail/package-announce/2016-February/177507.html