cache poisoning
termsecuritynetworking
Getting a resolver or proxy to store a forged answer, so every later client asking the same question is given the attacker's version.
The leverage is what makes it serious: one successful injection serves everybody behind that cache until the entry expires, which turns a single race won into a population-scale redirect. In DNS the race was against a 16-bit query identifier, which is why source-port randomisation was the emergency mitigation and DNSSEC the actual answer. The same shape appears wherever something caches on behalf of many - web caches, ARP tables, and any middlebox that remembers an answer to save asking again.
Also known as: dns spoofing