A memory leak flaw was found in ntpd's CRYPTO_ASSOC. If ntpd is configured to use autokey authentication, an attacker could send packets to ntpd that would, after several days of ongoing attack, cause it to run out of memory. Mitigation: Disable NTP autokey authentication. External References: https://github.com/ntp-project/ntp/blob/stable/NEWS#L91 http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-7701