1. IP SPOOFING By Ch. Rakesh Sharma

4. TCP/IP in 3 minutes or less Application Transport Interweb Network Access Physical TCP IP

7. IP Spoofing Sometimes on the internet, a girl named Alice is really a man named Yves

11. IP Spoofing – The Reset Victim - Bob Sucker - Alice Attacker - Eve 1. SYN – Let’s have a conversation 2. SYN ACK – Sure, what do you want to talk about? 3. RESET – Umm.. I have no idea why you are talking to me 4. No connection – Guess I need to take Bob out of the picture…

14. Mitnick Attack 1. Mitnick Flood’s server’s login port so it can no longer respond 2. Mitnick Probes the Workstation to determine the behaviour of its TCP sequence number generator 3. Mitnick discovers that the TCP sequence number is incremented by 128000 each new connection 4. Mitnick forges a SYN from the server to the terminal 5. Terminals responds with an ACK, which is ignored by the flooded port (and not visible to Mitnick) Server Workstation Kevin Mitnick 6. Mitnick fakes the ACK using the proper TCP sequence number 7. Mitnick has now established a one way communications channel

16. Session Hijack Alice Bob Eve I’m Bob! I’m Alice! 1. Eve assumes a man-in-the-middle position through some mechanism. For example, Eve could use Arp Poisoning, social engineering, router hacking etc... 2. Eve can monitor traffic between Alice and Bob without altering the packets or sequence numbers. 3. At any point, Eve can assume the identity of either Bob or Alice through the Spoofed IP address. This breaks the pseudo connection as Eve will start modifying the sequence numbers

18. DoS Attack Server Attacker Legitimate Users Interweb Fake IPs Service Requests Flood of Requests from Attacker Server queue full, legitimate requests get dropped Service Requests

20. DDoS Attack Server (already DoS’d) Attacker Target Servers Interweb 1. Attacker makes large number of SYN connection requests to target servers on behalf of a DoS’d server 2. Servers send SYN ACK to spoofed server, which cannot respond as it is already DoS’d. Queue’s quickly fill, as each connection request will have to go through a process of sending several SYN ACKs before it times out SYN SYN SYN SYN SYN ACK SYN ACK SYN ACK SYN ACK Queue Full