CPENT Iot And OT Exploitation Practice Question
During a hardware penetration test of an IoT device, the tester identifies a 4-pin header on the PCB. Using a multimeter, the tester measures ground on pin 1, 3.3V on pin 4, and observes fluctuating voltages on pins 2 and 3 during boot. What hardware interface do pins 2 and 3 most likely represent?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
UART (Universal Asynchronous Receiver-Transmitter)
UART (Universal Asynchronous Receiver-Transmitter) interfaces typically consist of 4 pins: VCC, GND, TX, and RX, where TX and RX show fluctuating voltage activity during transmission upon boot.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
UART (Universal Asynchronous Receiver-Transmitter)
Why this is correct
UART interfaces commonly feature VCC, GND, TX, and RX pins, presenting active data signal fluctuations during device bootup.
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JTAG (Joint Test Action Group)
Why it's wrong here
JTAG typically requires at least 4 signal pins (TDI, TDO, TCK, TMS) plus power and ground, making it a 5 or 6-pin interface.
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I2C (Inter-Integrated Circuit)
Why it's wrong here
I2C uses only two signal lines (SDA and SCL) plus power and ground, making it a 4-pin header, but UART is far more common for boot-time console logging.
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SPI (Serial Peripheral Interface)
Why it's wrong here
SPI requires at least 4 signal lines (MOSI, MISO, SCK, CS) plus power and ground, typically forming a 6-pin header.
About these practice questions
One of 276 original CPENT practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official EC-Council exam blueprint
This CPENT 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 CPENT exam.