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.

• ✓

  Default credentials

  Why this is correct

  Manufacturers frequently ship IoT devices with easily guessable or hardcoded default usernames and passwords (e.g., "admin/admin," "root/password"). Users often fail to change these factory settings, leaving devices highly susceptible to automated brute-force attacks, dictionary attacks, or simple credential stuffing. This vulnerability grants unauthorized access, allowing attackers to control the device, exfiltrate data, or use it as a pivot point for further network compromise.

• ✗

  SQL injection

  Why it's wrong here

  SQL injection is an attack vector primarily targeting web applications or backend systems that interact with relational databases by manipulating SQL queries. Most edge IoT devices, however, are designed with highly constrained resources and typically do not host SQL databases directly or expose SQL-queryable interfaces. Therefore, while a backend IoT platform might be vulnerable, SQL injection is generally not a direct attack vector against the IoT devices themselves.

• ✓

  Insecure protocols (MQTT, CoAP)

  Why this is correct

  Protocols like Message Queuing Telemetry Transport (MQTT) and Constrained Application Protocol (CoAP) are optimized for lightweight communication in resource-constrained IoT environments. However, their default implementations frequently lack robust encryption (e.g., TLS/DTLS is optional or often misconfigured) and strong authentication mechanisms. This absence of security allows attackers to easily eavesdrop on sensitive data, inject malicious commands, or impersonate legitimate devices, compromising data integrity and device control.

• ✓

  Firmware reversing

  Why this is correct

  Firmware reversing involves extracting the embedded software from an IoT device, typically through physical access or software exploits, and then analyzing its binary code. This process aims to uncover hardcoded secrets like API keys, cryptographic material, or default credentials, identify buffer overflows, or discover logic flaws within the device's operational programming. Such vulnerabilities, once identified, can be exploited to gain unauthorized access, modify device behavior, or compromise the entire IoT ecosystem.

• ✗

  ARP spoofing

  Why it's wrong here

  Address Resolution Protocol (ARP) spoofing is a Layer 2 network attack where an attacker sends forged ARP messages to associate their MAC address with the IP address of a legitimate network device. This allows the attacker to intercept, modify, or block network traffic intended for the legitimate device. While IoT devices can certainly be *targets* or *victims* of ARP spoofing within a local network, it is a general network-level attack and not an attack vector specific to the unique vulnerabilities or characteristics inherent in IoT devices themselves.

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