About Module 01 – UART Hacking

Welcome to the first module in TrainSec’s Hardware Hacking Expert Level 2 series. This is where we take the solid foundations from Level 1 and push them into the real world of device exploitation. You have already learned how to recognize and handle hardware interfaces. Now it is time to weaponize those skills.

This module is all about UART. We will strip away the theory and go hands-on with real devices, building tools, capturing data, breaking protections, and developing working exploits. By the end of this journey, UART will no longer be just another debugging port. It will be an attack vector you can confidently own.

Module 01 introduces students to one of the most widely available yet underestimated hardware interfaces: UART (Universal Asynchronous Receiver-Transmitter). The training combines theoretical background with extensive hands-on practice, guiding you from the basics of pin identification to advanced exploitation in both embedded and industrial (OT/ICS) systems.

The journey begins with the fundamentals. You will understand why UART remains a critical backdoor left by engineers and how it exposes valuable system information. From there, you will locate and validate UART connections, capture debug logs, and bypass weak login protections. By the end of this stage you will have mastered the essential reconnaissance and access methods that form the gateway to deeper exploitation.

Once the basics are in place, you extend into the operational technology world where UART underpins protocols like RS232, RS422, and RS485. You will practice tapping into live OT lines, distinguishing communication wires from power or sensor lines, and translating OT signals back into UART for analysis. With custom-built RS485-to-UART adaptors you will capture and reverse engineer OT traffic, mapping packet structures and uncovering protocol logic. At this level you also build your own Python-based man in the middle relay and inject crafted commands, learning how attackers move from passive listening to active control.

The final stage is where UART exploitation becomes a complete offensive workflow. You will develop brute-force methods to break authentication, extract entire firmware images for offline analysis, and challenge secure boot protections to expose weaknesses. The training culminates in advanced exploitation techniques including man in the middle on OT traffic, fault injection, and bypassing hardware kill-switch protections. By the end of Module 01 you will have a complete toolkit for identifying, analyzing, and exploiting UART in both consumer and industrial environments, establishing a strong foundation for advanced hardware hacking.

What Students Will Learn in This Module

  • Basic Techniques

    • Why UART is one of the most valuable hardware attack surfaces

    • How to identify and validate UART pins on real devices

    • Capturing and interpreting boot logs and debug messages

    • Bypassing weak or misconfigured UART login prompts

  • Advanced Techniques

    • Understanding how UART underpins OT protocols such as RS232, RS422, and RS485

    • Tapping into live OT communication lines and distinguishing data wires from power or sensors

    • Using custom RS485-to-UART adaptors to capture traffic

    • Reverse engineering OT protocol frames and mapping logic

    • Building a Python-based man in the middle relay to intercept and modify traffic

    • Injecting crafted commands into live OT systems

  • Expert Techniques

    • Developing brute-force approaches to break UART authentication

    • Extracting complete firmware images for offline analysis

    • Challenging and bypassing secure boot protections

    • Performing advanced UART exploitation including MITM, fault injection, and hardware kill-switch bypass

    • Creating and executing a custom exploit that ties together the full workflow

Prerequisites for This Module

  • Completion of Hardware Hacking Expert – Level 1  - (at least classes 1-8) or equivalent.

  • Basic electronics (voltage, current, ground)  - class 1 in Hardware Hacking Expert – Level 1.

  • UART fundamentals (RX, TX, baud rate) - class 7 in Hardware Hacking Expert – Level 1.

  • Soldering and hardware handling experience.

  • Familiarity with logic analyzers and USB-to-UART tools  - class 5 in Hardware Hacking Expert – Level 1.

  • Basic knowledge of RS232/422/485 - class 8 in Hardware Hacking Expert – Level 1.

  • Linux shell usage.

  • Python programming basics.

  • Safe lab practices with circuits and OT devices - class 5 in Hardware Hacking Expert – Level 1.

1 Lesson