Certified Ethical Hacker (CEH v13) — Question 41

An ethical hacker is performing a network scan to evaluate the security of a company's IT infrastructure. During the scan, he discovers an active host with multiple open ports running various services. The hacker uses TCP communication flags to establish a connection with the host and starts communicating with it. He sends a SYN packet to a port on the host and receives a SYN/ACK packet back. He then sends an ACK packet for the received SYN/ACK packet, which triggers an open connection. Which of the following actions should the ethical hacker perform next?

Answer options

• A. Send a PSH packet to inform the receiving application about the buffered data.
• B. Conduct a vulnerability scan on the open port to identify any potential weaknesses.
• C. Scan another port on the same host using the SYN, ACK, and RST flags.
• D. Send a FIN or RST packet to close the connection.

Correct answer: B

Explanation

The ethical hacker should conduct a vulnerability scan on the open port to identify any potential weaknesses, as this step is crucial in assessing the security posture of the service running on that port. Sending a PSH packet is unnecessary at this stage, scanning another port without assessing the current one skips important information, and closing the connection prematurely would not yield any valuable insights.