Quick Answer
The correct answer is remote code execution via SMB vulnerabilities. Port 445/TCP is used by Microsoft SMB (Server Message Block) over a direct TCP connection, and this service has historically been plagued by critical flaws like EternalBlue (MS17-010), which allowed the WannaCry ransomware to spread by executing arbitrary code on unpatched Windows systems. On the Certified Ethical Hacker CEH exam, this question tests your ability to map a specific open port to its most dangerous risk, often appearing in vulnerability assessment scenarios where you must prioritize patching. A common trap is confusing port 445 with file-sharing risks like unauthorized access, but the exam emphasizes that the primary threat is remote code execution due to SMB’s deep kernel-level integration. Memory tip: think “445 = Four Four Five = Forced Full File-system Execution” to recall that an open SMB port can lead to complete system compromise.
This CEH practice question tests your understanding of footprinting, reconnaissance and scanning. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
During a vulnerability scan with Nessus, you find that port 445/TCP is open on a Windows server. Which of the following is the MOST likely associated risk?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
SNMP community string brute-forcing
Why wrong: SNMP uses UDP ports 161/162.
Remote code execution via SMB vulnerabilities
SMB on port 445 has known RCE vulnerabilities.
HTTP directory traversal
Why wrong: HTTP uses port 80/443.
DNS cache poisoning
Why wrong: DNS uses port 53.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Remote code execution via SMB vulnerabilities
Port 445/TCP is used by Microsoft SMB (Server Message Block) over a direct TCP connection, commonly known as SMB over TCP. SMB has historically been plagued by critical remote code execution vulnerabilities, most notably EternalBlue (MS17-010) exploited by WannaCry. Therefore, an open SMB port on a Windows server presents a high risk of remote code execution if unpatched.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
SNMP community string brute-forcing
Remote code execution via SMB vulnerabilities
Why this is correct
SMB on port 445 has known RCE vulnerabilities.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
HTTP directory traversal
Why it's wrong here
HTTP uses port 80/443.
DNS cache poisoning
Why it's wrong here
DNS uses port 53.
Common exam traps
The trap here is that candidates may associate port 445 with file sharing only and overlook its history of critical remote code execution vulnerabilities, instead choosing a more generic or unrelated attack vector like HTTP directory traversal.
Detailed technical explanation
SMB operates as a network file sharing protocol that uses named pipes and authenticated sessions. The SMBv1 protocol, which lacks proper session security, allowed the EternalBlue exploit to send specially crafted packets that triggered a buffer overflow in the SMB driver (srv2.sys), enabling arbitrary code execution with SYSTEM privileges. Even in modern environments, misconfigured SMB shares or unpatched systems remain a common entry point for lateral movement.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Footprinting, Reconnaissance and Scanning — study guide chapter
Learn the concepts, then practise the questions
Footprinting, Reconnaissance and Scanning practice questions
Targeted practice on this topic area only
All CEH questions
1,010 questions across all exam domains
Certified Ethical Hacker CEH study guide
Full concept coverage aligned to exam objectives
CEH practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise CEH questions linked to Footprinting, Reconnaissance and Scanning.
Practise CEH questions linked to Enumeration and System Hacking.
Practise CEH questions linked to Malware, Social Engineering and Network Attacks.
Practise CEH questions linked to Web Application and Injection Attacks.
Practise CEH questions linked to Introduction to Ethical Hacking.
Practise CEH questions linked to Scanning Networks and Enumeration.
Practise CEH questions linked to Vulnerability Analysis and System Hacking.
Practise CEH questions linked to Advanced Topics: Wireless, Cloud, IoT, Cryptography.
Practise CEH questions linked to Footprinting and Reconnaissance.
Practise CEH questions linked to Network and Web Application Attacks.
Practise CEH questions linked to Wireless, IoT and Cloud Security.
Practise CEH questions linked to Cryptography and Malware Analysis.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Footprinting, Reconnaissance and Scanning — This question tests Footprinting, Reconnaissance and Scanning — Read the scenario before looking for a memorised answer..
The correct answer is: Remote code execution via SMB vulnerabilities — Port 445/TCP is used by Microsoft SMB (Server Message Block) over a direct TCP connection, commonly known as SMB over TCP. SMB has historically been plagued by critical remote code execution vulnerabilities, most notably EternalBlue (MS17-010) exploited by WannaCry. Therefore, an open SMB port on a Windows server presents a high risk of remote code execution if unpatched.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Last reviewed: Jun 24, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.