DNS Spoofing or DNS Cache poisoning
Prerequisite – Domain Name Server
Before Discussing DNS Spoofing, First, discuss what is DNS.
A Domain Name System (DNS) converts a human-readable name (such as www.geeksforgeeks.org) to a numeric IP address. The DNS system responds to one or more IP-address by which your computer connects to a website (such as geeksforgeeks.org) by using one of the IP-address.
There is not only one DNS server. There are series of DNS servers used to resolve the domain name. DNS uses cache to work efficiently so that it can quickly refer to DNS lookups it’s already performed rather than performing a DNS lookup over and over again.
Although DNS caching increase the speed of the domain name resolution process But the major change in the domain then takes a day to reflect worldwide.
DNS Spoofing means getting a wrong entry or IP address of the requested site from the DNS server. Attackers find out the flaws in the DNS system and take control and will redirect to a malicious website.
In above image –
- Request to Real Website: User hits a request for a particular website it goes to the DNS server to resolve the IP address of that website.
- Inject Fake DNS entry: Hackers already take control over the DNS server by detecting the flaws and now they add false entries to the DNS server.
- Resolve to Fake Website: Since the fake entry in the DNS server redirect the user to the wrong website.
To Prevent From DNS Spoofing –
DNS Security Extensions (DNSSEC) is used to add an additional layer of security in the DNS resolution process to prevent security threats such as DNS Spoofing or DNS cache poisoning.
DNSSEC protects against such attacks by digitally ‘signing’ data so you can be assured it is valid.