Learn in the textbookAttacks on Networks and Communication Paths
DefinitionDNS cache poisoning (DNSキャッシュポイズニング) is an attack that slips false entries into the name-resolution information a DNS server (DNSサーバ) keeps temporarily, so that users are sent to a fake site.
ExplanationDNS is the name-resolution system that looks up a device's IP address from its domain name, and a DNS server keeps the results it has looked up as a cache (キャッシュ, temporary storage for reuse). While the cache is poisoned, every user who asks that DNS server about the domain name is affected. This can lead to login details and other information being entered on the fake site and stolen, and DNSSEC, which uses digital signatures to verify that DNS responses are genuine, is one countermeasure.
AnalogyIt is like someone writing a fake shop's address onto the map at a town information desk as the location of a real shop. The people who ask for the shop by its correct name are exactly the ones sent straight to the fake one.
Memory hook"Poisoning" pictures slipping poison into the cache, the pool where name-resolution information collects.