PRESENTATIONON

IP SPOOFING

SpoofingIs a situation in which One person or program Successfully inserts false Or misleading information in e-mail or Netnews headers.Also known as header forgery.

overview

•TCP/IP-in brief•IP spoofing Basic overview IP spoofing-How it works Examples of spoofing attacks Mitnick attack Session Hijack Dos attack•Defending against the threat•Conclusion

TCP/IP

•General use of term describes the architecture upon which the Interweb is built.•TCP and IP are specific protocols whithin that architecture.

Appilication

Transport

Interweb

NetworkAccess

Physical

TCP/IP

TCP

IP

IP•IP is the internet layer protocol.•Does not guarantee delivery or ordering only does its best to packets from a source address to a destination address.•IP address are used to express the source and destination.•IP assumes that each address is unique whithin the network.

TCP

•TCP is the transport layer protocol.•It guarantee delivery and ordering,but relies upon IP to move packets proper destination.•Port number are used to express source and destination.•Destination port is assumed to be awaiting packets of data.

IP Spoofing

•Basically, IP spoofing is lying about an IP address.•Normally, the source address is incorrect.•Lying about the source lets an attacker assume a new identity.•Because the source address is not the same as the attacker’s address, any replies generated by•the destination will not be sent to the attacker.

IP Spoofing

•Blind and non blind spoofing.•Attacker must have an alternate way to spy on traffic/predict response.•To maintain a connection,Attacker must adhere to protocol requirements.

IP Spoofing-how it works!!•IP spoofing used to take control of a session.•Attacker normally within a LAN/on the communication path between server and client.•Not blind,since the attacker can see traffic from both server and client.

Example of spoofing attacks

•Mitnick Attack•Session Hijack•Dos Attack

Mitnick attack

•Merry X-mas! Mitnick hacks a Diskless Workstation on December 25,1994•The victim-Tsutomu Shinomura•The attack-IP spoofing and abuse of trust ralationship between diskless terminal and login server.

Why Mitnick attack worked

•Mitnick abused the trust ralationship between the server and workstation•He flooded the server to prevent communication between it and the workstation•Used math skillz to determine the TCP sequence number algorithm(i.e.add 128000)•This allowed Mitnick to open a connection without seeing the workstation outgoing sequence numbers and without the server interrupting his attack

Dos Attack

•Denial of service(Dos) attack aimed preventing clients from accessing a service.•IP spoofing can be used to create Dos attacks.

•The attacker a large of requests from various IP addresses to fill services queue.•With the services queue filled,legitimate user’s cannot use the service.•Dos becomes more dangerous if spread to multiple computers.

Dos Attack

IP spoofing can be defended against in a number of ways:

•AS mentioned other in the architecture model may reveal spoofing. •TCP sequence numbers are often used in this manner

•Makes if difficult to proper sequence number if the attacker is blind

•Filtering•“Smart” routers can detect IP address that are outside its domain i.e. Egress filtering•“smart “ server block IP range that appear to be conducting a Dos i.e. Ingress filtering

IP Spoofing-Defending

Encryption And Authentication

•Authentication is a mechanism where by the receiver of a transaction or message can be confident of the identity of sender and the integrity of message.

•Use of encryption schemes.•Verification of identity of incoming packets.

IP Spoofing-Defending