The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.
nwtime.org/ntp428p9_release/
support.ntp.org/bin/view/Main/NtpBug3082
support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
www.securityfocus.com/bid/94448
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
security.FreeBSD.org/advisories/FreeBSD-SA-16:39.ntp.asc
www.exploit-db.com/exploits/40806/
www.kb.cert.org/vuls/id/633847