NTP "NAK to the Future"

Crypto-NAK packets can be used to cause ntpd to accept time from unauthenticated ephemeral symmetric peers by bypassing the authentication required to mobilize peer associations. This module sends these Crypto-NAK packets in order to establish an association between the target ntpd instance and t...

ntp: authentication doesn't protect symmetric associations against DoS attacks

A denial of service flaw was found in the way NTP hosts that were peering with each other authenticated themselves before updating their internal state variables. An attacker could send packets to one peer host, which could cascade to other peers, and stop the synchronization process among the...