NTP Daemon CRYPTO_NAK Denial Of Service Vulnerability (CVE-2016-4957)

A denial of service vulnerability exists in the Network Time Protocol daemon (NTPD). The vulnerability is due to a null pointer dereference when handling crypto-NAK packets. A remote attacker can exploit this vulnerability by sending an unsolicited crypto-NAK packet to the target service. Successful exploitation may result in denial-of-service conditions.