Service interruption via pulsing DNS amplification

Network amplification in Technitium DNS Server 11.0.2 and earlier allows remote attackers to interrupt services with pulsing DNS traffic. The recursive resolver aggregates repeated queries for one name, accepts a large delayed answer, then rapidly returns that answer to every waiting request. Exploitation requires source-address spoofing, an attacker-controlled domain and authoritative name server, and network access to a recursive resolver; the resulting burst can saturate a third-party target.