NTP before 4.2.8p9 changes the peer structure to the interface it receives the response from a source, which allows remote attackers to cause a denial of service (prevent communication with a source) by sending a response for a source to an interface the source does not use.
nwtime.org/ntp428p9_release/
rhn.redhat.com/errata/RHSA-2017-0252.html
support.ntp.org/bin/view/Main/NtpBug3072
support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
www.securityfocus.com/bid/94453
www.securitytracker.com/id/1037354
bto.bluecoat.com/security-advisory/sa139
h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us
www.kb.cert.org/vuls/id/633847