Book Image

Fuzzing Against the Machine

By : Antonio Nappa, Eduardo Blázquez
Book Image

Fuzzing Against the Machine

By: Antonio Nappa, Eduardo Blázquez

Overview of this book

Emulation and fuzzing are among the many techniques that can be used to improve cybersecurity; however, utilizing these efficiently can be tricky. Fuzzing Against the Machine is your hands-on guide to understanding how these powerful tools and techniques work. Using a variety of real-world use cases and practical examples, this book helps you grasp the fundamental concepts of fuzzing and emulation along with advanced vulnerability research, providing you with the tools and skills needed to find security flaws in your software. The book begins by introducing you to two open source fuzzer engines: QEMU, which allows you to run software for whatever architecture you can think of, and American fuzzy lop (AFL) and its improved version AFL++. You’ll learn to combine these powerful tools to create your own emulation and fuzzing environment and then use it to discover vulnerabilities in various systems, such as iOS, Android, and Samsung's Mobile Baseband software, Shannon. After reading the introductions and setting up your environment, you’ll be able to dive into whichever chapter you want, although the topics gradually become more advanced as the book progresses. By the end of this book, you’ll have gained the skills, knowledge, and practice required to find flaws in any firmware by emulating and fuzzing it with QEMU and several fuzzing engines.
Table of Contents (18 chapters)
Part 1: Foundations
Part 2: Emulation and Fuzzing
Part 3: Advanced Concepts
Chapter 12: Conclusion and Final Remarks

QEMU Execution Modes and Fuzzing

In this chapter, we will cover QEMU modes, namely the user mode and full-system emulation. Once we understand the difference, we will dig into fuzzing code with these two different modes. In the first case, we will be able to fuzz a program through the interface it exposes to the user, that is, stdin. In the second case, we will have to choose our battle and select a component of the operating system, for example, a piece of the network stack, a specific device driver interface, or in the case of an embedded operating system, a particular task such as the memory allocator or the CPU scheduler.

This chapter will cover the following main topics:

  • QEMU user mode
  • QEMU system mode
  • Static versus dynamic fuzzing
  • Sophisticated methods with constraint solving
  • Advantages of AFL and AFL++ versus my own fuzzer