CEH Practice Question: Advanced Topics: Wireless, Cloud, IoT, Cryptography

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Buffer overflow and command injection

  Why it's wrong here

  The scenario provides no information to suggest the presence of buffer overflow vulnerabilities or command injection flaws within the IoT device's software. These types of attacks typically exploit specific coding errors in input handling or memory management, which are not indicated by the description focusing on default authentication and protocol usage. The problem statement points towards network-level access and data transmission issues, rather than code execution exploits.

• ✓

  Default credentials and cleartext communication

  Why this is correct

  The scenario explicitly states the use of "default credentials," which are easily guessable or publicly known, allowing unauthorized access to the IoT device or its MQTT broker. Furthermore, the absence of any mention of TLS/SSL for the MQTT protocol implies that communication occurs in "cleartext." This means all transmitted data, including sensitive information and authentication tokens, is unencrypted and can be easily intercepted and read by an attacker using packet sniffing tools.

• ✗

  Insecure firmware and hardcoded backdoor

  Why it's wrong here

  While insecure firmware and hardcoded backdoors are significant vulnerabilities in many IoT devices, the provided scenario does not offer any specific details or indicators pointing towards these types of device-level compromises. The problem description specifically highlights the use of "default credentials" and the "MQTT protocol," which are network-level configuration and protocol issues, not related to the integrity of the device's operating system or hidden access mechanisms within its firmware.

• ✗

  Weak encryption and replay attack

  Why it's wrong here

  The scenario implies a complete lack of encryption rather than "weak encryption," as MQTT often operates without TLS on its default unencrypted port (1883). Therefore, describing the encryption as merely "weak" is inaccurate when there might be none at all. While a replay attack could theoretically occur if unencrypted messages are captured and resent, the more immediate and fundamental vulnerabilities described by the scenario are the ease of initial access via default credentials and the complete exposure of data due to cleartext transmission.

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