DNS cache poisoning

A domain name server converts human readable domain to numerical values which is used for communication between the client and web. When DNS server receives unauthentic data from the client computer, it is considered poisoned, thus this further lead to supplying unauthentic data to client by server, this unauthentic data is decided by attackers target.

In DNS cache poisoning, cache is poisoned for particular domain name also it can be done for one user or for several users by poisoning the downstream servers. When the cache is poisoned for one particular domain on single DNS than when the client will go on that one particular link it will redirect the client to another address which was injected by attacker to cache poison.

So this type of attack redirect the targeted domain to another targeted domain.

Now it is up to you that how can you use it in your hacking purpose. One simple example is given below. 

Suppose you want to hack facebook account than first create the fake page to which you want to redirect the user. HOW TO MAKE PHISHING PAGE. Now poison the cache for the targeted user so that when user enter facebook.com it will redirect to your fake same looking page and will enter the user name and password.
For poisoning cache you can use cain & abel as shown in below tutorial.  

Cache Poisoning Tutorial