CEH-001 Exam Dumps : Certified Ethical Hacker (CEH)

After a client sends a connection request (SYN) packet to the server, the server will respond (SYN-ACK) with a sequence number of its choosing, which then must be acknowledged (ACK) by the client. This sequence number is predictable; the attack connects to a service first with its own IP address, records the sequence number chosen, and then opens a second connection from a forged IP address. The attack doesn't see the SYN-ACK (or any other packet) from the server, but can guess the correct responses. If the source IP address is used for authentication, then the attacker can use the one-sided communication to break into the server. What attacks can you successfully launch against a server using the above technique?

John runs a Web server, IDS and firewall on his network. Recently his Web server has been under constant hacking attacks. He looks up the IDS log files and sees no intrusion attempts but the Web server constantly locks up and needs rebooting due to various brute force and buffer overflow attacks but still the IDS alerts no intrusion whatsoever. John becomes suspicious and views the Firewall logs and he notices huge SSL connections constantly hitting his Web server. Hackers have been using the encrypted HTTPS protocol to send exploits to the Web server and that was the reason the IDS did not detect the intrusions. How would John protect his network from these types of attacks?

What are two things that are possible when scanning UDP ports? (Choose two.