TL;DR: DNS Cache Poisioning;

• Impersonating an Authoritative nameserver and forging a reply to the DNS server requesting for information,

• Reply gets cached (meaning DNS server ends up caching wrong information)

• e.g DNS server ask for IP address of a Domain name Attackers forges a reply with the wrong IP and wrong IP gets cached

Extras:

a) What is a DNS Server :

DNS translates domain names to IP addresses so browsers can load Internet resources. the DNS Server handles this task of finding the right IP address for the domain name entered

b) What is a Nameserver:

They hold information about domain names and their associated ip addresses