The answer is default credentials and insecure protocols. These two attack vectors are the most common entry points for compromising IoT devices because manufacturers often ship devices with factory-set usernames and passwords that users neglect to change, while also relying on protocols like plaintext MQTT that lack encryption, allowing attackers to intercept or inject commands. On the Certified Ethical Hacker CEH exam, this concept tests your understanding of the IoT attack surface and how simple misconfigurations—rather than sophisticated exploits—often lead to breaches; a common trap is overlooking that insecure protocols include both unencrypted data transmission and weak authentication mechanisms. To remember these two vectors, think of the mnemonic “DIP” for Default credentials and Insecure Protocols, which together form the low-hanging fruit attackers target first in any IoT environment.
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 attack vectors against IoT devices? (Select TWO.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Default credentials left unchanged
IoT devices often have default credentials that are not changed, and they use insecure protocols like MQTT without encryption. These are common entry points for attackers.
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.
✓
Default credentials left unchanged
Why this is correct
Many IoT devices ship with default usernames/passwords that users fail to change.
Related concept
Read the scenario before looking for a memorised answer.
✗
Regular firmware updates
Why it's wrong here
Regular updates are a security best practice.
✓
Insecure protocols such as plaintext MQTT
Why this is correct
Plaintext MQTT lacks encryption and authentication, making it vulnerable to eavesdropping and tampering.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use of strong encryption protocols
Why it's wrong here
Use of strong encryption is a security measure, not an attack vector.
✗
Use of certificate-based authentication
Why it's wrong here
Certificate-based authentication strengthens security, it is not an attack vector.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→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.
Identify which CEH exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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: Default credentials left unchanged — IoT devices often have default credentials that are not changed, and they use insecure protocols like MQTT without encryption. These are common entry points for attackers.
What should I do if I get this CEH question wrong?
Identify which CEH exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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. Which TWO of the following are common attack vectors against IoT devices? (Select 2)
medium
✓ A.Default credentials
B.Firmware extraction via JTAG
✓ C.Insecure protocols like MQTT without encryption
D.Replay attacks on encrypted sessions
E.SQL injection
Why A: Default credentials and insecure protocols (e.g., MQTT without TLS) are common IoT attack vectors; firmware extraction is a technique, not a vector; SQL injection is more common in web apps; replay attacks can occur but are not specific to IoT.
Variation 2. Which THREE of the following are common attack vectors against IoT devices? (Choose three.)
hard
✓ A.Firmware reversing
B.Container escape
C.SQL injection
✓ D.Default credentials
✓ E.Insecure protocols (e.g., MQTT, CoAP)
Why A: Default credentials, insecure protocols like MQTT, and firmware reversing are all common IoT attack vectors. SQL injection is more typical for web applications.
Variation 3. Which THREE of the following are common attack vectors against IoT devices?
hard
A.Container escape
✓ B.Insecure protocols (e.g., MQTT, CoAP without encryption)
✓ C.Firmware reversing and extraction of hardcoded secrets
D.TLS stripping attack
✓ E.Default credentials
Why B: Default credentials, insecure protocols (e.g., MQTT without TLS), and firmware reversing (to find hardcoded secrets) are common IoT attack vectors. TLS stripping is a network attack, and container escape is a cloud/container attack.
Last reviewed: Jun 21, 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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