It was found that the fix for CVE-2014-9750 was incomplete: three issues were found in the value length checks in ntp_crypto.c, where a packet with particular autokey operations that contained malicious data was not always being completely validated. Receipt of these packets can cause ntpd to crash. http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-7691
