GIAC Penetration Tester (GPEN) — Question 22

During a penetration test we determine that TCP port 22 is listening on a target host. Knowing that SSHD is the typical service that listens on that port we attempt to validate that assumption with an SSH client but our effort Is unsuccessful. It turns out that it is actually an Apache webserver listening on the port, which type of scan would have helped us to determine what service was listening on port 22?

Answer options

• A. Version scanning
• B. Port scanning
• C. Network sweeping
• D. OS fingerprinting

Correct answer: A

Explanation

Version scanning is designed to identify the specific services and their versions running on open ports, which would have confirmed if SSHD or another service like Apache was listening on port 22. Port scanning only detects open ports without providing detailed service information, while network sweeping focuses on mapping the network and OS fingerprinting aims to identify the operating system in use, neither of which would give clarity on the service itself.