Explain why it is important that TCP sequence numbers are ch

Explain why it is important that TCP sequence numbers are chosen in a non-predictable manner. In the absence of other controls, what can an attacker accomplish if a sequence number can be predicted?

Solution

TCP sequence number is used uniquely indentify packet send from one send host to other host.TCP acknowledges packet because of sequence numberThe host who wants to start connection,it generates Initial Sequence Number(ISN).ISN is very favourite for attacker as ISN is always issue for security.Hence,every system uses different mechanism to generate random sequence number,So that i would difficuilt for attacker to figure out sequence number.Hence,it is important to TCP sequence numbers to choose in a non-predictable manner.

What will happen if attacker accomplish if a sequence number?

Suppose,there are 2 hosts i.e.Host 1 and Host 2.

Now,consider attacker is between Host 1 and  Host 2.

Attacker will do DOS(Deniel of Service) attack to Host 2.so,that it will stop working.Hence ,attacker will acts as Host 2.

If attacker is able to predicte sequence number generated from Host 2,it will create fake packet.It will send this packet to Host 1.

Host 1 assumes that this packets are coming from Host 2 as sequence number is matching.Hence,attacker takes advantages of this situation and try to send malicious code to Host 1.Hence ,attacker will be able to control full packet control mechanism