A DNS, much like a phonebook is directory that holds the information of where the website/web application for a given URL is.
It is a vital element in the way that we access the internet and keeping it secure is a top priority for any business that depends on the internet.
Not all DNS records are public. For example, in a private organisation where sensitive data needs to be accessible only by employees, a private DNS is used. Having said that, even private DNS records don’t require authentication as the technology behind a DNS came up at a time when it wasn’t a necessity. Someone who manages to infiltrate your intranet would be able to query your private DNS without raising any alarm if you don’t have DNS security measures in place.
A compromised DNS means that malicious actors can reroute traffic originally intended to your website and harvest their user data.