The answer is the use of default credentials and insecure protocols such as MQTT without TLS. These two weaknesses are frequently exploited because many IoT devices ship with factory-set usernames and passwords like 'admin/admin' or hard-coded credentials embedded in firmware, while also relying on protocols like MQTT that transmit data in plaintext if TLS is not enforced. Attackers can easily discover default credentials through simple web searches or Shodan scans, and intercept unencrypted traffic to gain unauthorized access to the device and pivot into the broader network. On the Certified Ethical Hacker CEH exam, this topic tests your understanding of the OWASP IoT Top 10 and often appears in questions about reconnaissance or exploitation phases, with a common trap being to overlook that insecure protocols are just as critical as weak passwords. Remember the mnemonic "DIP" for Default credentials, Insecure protocols, and Plaintext traffic—if any one is present, the device is vulnerable.
CEH Practice Question: Advanced Topics: Wireless, Cloud, IoT, Cryptography
This CEH practice question tests your understanding of advanced topics: wireless, cloud, iot, cryptography. 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.
Which TWO of the following are common weaknesses in IoT devices that are often exploited by attackers?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use of default or hard-coded credentials
Option C is correct because many IoT devices ship with default usernames and passwords (e.g., 'admin/admin') or hard-coded credentials embedded in firmware. Attackers can easily discover these through simple web searches or Shodan scans, then gain unauthorized access to the device and potentially the entire network.
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.
✗
Use of hardware security modules (HSM)
Why it's wrong here
HSMs enhance security, not a weakness.
✗
Implementation of secure boot
Why it's wrong here
Secure boot is a security feature, not a weakness.
✓
Use of default or hard-coded credentials
Why this is correct
Correct: Many IoT devices ship with default usernames/passwords that are not changed.
Related concept
Read the scenario before looking for a memorised answer.
✓
Use of insecure protocols such as MQTT without TLS
Why this is correct
Correct: Unencrypted MQTT is a common vulnerability.
Related concept
Read the scenario before looking for a memorised answer.
✗
Firmware update mechanism with signed updates
Why it's wrong here
Signed updates are a security measure, not a weakness.
Common exam traps
Common exam trap: answer the scenario, not the keyword
EC-Council often tests the distinction between security controls (HSM, secure boot, signed updates) and actual vulnerabilities (default credentials, cleartext protocols), so candidates mistakenly select secure features as weaknesses.
Detailed technical explanation
How to think about this question
MQTT without TLS (Option D) transmits data in cleartext, allowing attackers to intercept messages, inject commands, or replay captured packets. In real-world attacks, default credentials (Option C) are often combined with MQTT over port 1883 to compromise smart home hubs or industrial sensors, leading to botnet recruitment (e.g., Mirai).
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 practitioner preparing for the CEH exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CEH question in full detail.
Advanced Topics: Wireless, Cloud, IoT, Cryptography — This question tests Advanced Topics: Wireless, Cloud, IoT, Cryptography — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use of default or hard-coded credentials — Option C is correct because many IoT devices ship with default usernames and passwords (e.g., 'admin/admin') or hard-coded credentials embedded in firmware. Attackers can easily discover these through simple web searches or Shodan scans, then gain unauthorized access to the device and potentially the entire network.
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.
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 →
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.
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.