The answer is Nessus, as it is the best vulnerability scanner tool for conducting a thorough vulnerability scan against a target network. Nessus automates the identification of known vulnerabilities, misconfigurations, and missing patches by leveraging a vast plugin database of NASL scripts, performing non-intrusive checks against services and operating systems, and correlating results directly with CVE entries to provide actionable risk ratings. On the Certified Ethical Hacker CEH exam, this question tests your ability to distinguish between dedicated vulnerability scanners and general-purpose tools like Nmap or Metasploit; a common trap is choosing Nmap because it can also find open ports, but Nessus is purpose-built for the full vulnerability assessment lifecycle. Remember the memory tip: “Nessus Nails CVEs” — if the task is to scan for known vulnerabilities with risk ratings, Nessus is the dedicated choice.
CEH Footprinting, Reconnaissance and Scanning Practice Question
This CEH practice question tests your understanding of footprinting, reconnaissance and scanning. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A penetration tester is conducting a vulnerability scan against a target network. Which of the following tools is BEST suited for this task?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Nessus
Nessus is a dedicated vulnerability scanner that automates the process of identifying known vulnerabilities, misconfigurations, and missing patches across a target network. It uses a large plugin database (e.g., NASL scripts) to perform non-intrusive checks against services and operating systems, making it the best tool for a vulnerability scan. Unlike general-purpose tools, Nessus is specifically designed to correlate scan results with CVE entries and provide risk ratings, which is the core requirement of a vulnerability assessment.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Nessus
Why this is correct
Nessus is a comprehensive vulnerability scanner that checks for thousands of vulnerabilities.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Nmap
Why it's wrong here
Nmap is primarily a port scanner and can run some vulnerability scripts, but Nessus is a dedicated vulnerability scanner.
✗
Wireshark
Why it's wrong here
Wireshark is a packet analyzer, not a vulnerability scanner.
✗
Metasploit
Why it's wrong here
Metasploit is an exploitation framework, not primarily a vulnerability scanner (though it has auxiliary scanners).
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse network scanning (Nmap) with vulnerability scanning (Nessus), assuming that any tool that discovers open ports can also assess vulnerabilities, but CEH distinguishes between reconnaissance tools and dedicated vulnerability assessment tools.
Detailed technical explanation
How to think about this question
Nessus operates by sending crafted probes to target hosts and analyzing responses against a library of over 100,000 plugins, each targeting a specific vulnerability (e.g., CVE-2023-XXXX). It uses a client-server architecture where the Nessus daemon (nessusd) manages scans and stores results in a backend database, allowing for scheduled scans and compliance checks (e.g., CIS benchmarks). In a real-world scenario, a penetration tester would first run Nessus to generate a prioritized list of vulnerabilities, then use Nmap for service enumeration and Metasploit for targeted exploitation, but Nessus alone is the correct tool for the initial vulnerability scan.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CEH question in full detail.
Footprinting, Reconnaissance and Scanning — This question tests Footprinting, Reconnaissance and Scanning — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Nessus — Nessus is a dedicated vulnerability scanner that automates the process of identifying known vulnerabilities, misconfigurations, and missing patches across a target network. It uses a large plugin database (e.g., NASL scripts) to perform non-intrusive checks against services and operating systems, making it the best tool for a vulnerability scan. Unlike general-purpose tools, Nessus is specifically designed to correlate scan results with CVE entries and provide risk ratings, which is the core requirement of a vulnerability assessment.
What should I do if I get this CEH question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A security analyst is conducting a vulnerability scan on a web server using Nessus. After the scan, they notice that the server's performance has degraded significantly, and some services have become unresponsive. Which of the following actions could have prevented this issue?
medium
A.Increase the scan intensity to complete faster and reduce the load
✓ B.Configure Nessus to use a 'safe' scan policy that disables disruptive plugins
C.Use a different scanner like OpenVAS which is less intrusive
D.Run the scan during peak hours to blend in with normal traffic
Why B: Option B is correct because Nessus 'safe' scan policies disable plugins known to cause service disruption, such as those performing denial-of-service tests or exploiting vulnerabilities that may crash services. By using a safe policy, the analyst avoids aggressive checks that can degrade server performance or cause unresponsiveness, which is a common risk during vulnerability scanning.
Last reviewed: Jun 24, 2026
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This CEH practice question is part of Courseiva's free EC-Council certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CEH exam.
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