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


In this chapter, we have surely gone beyond expectations. We have taken an obscure, poorly documented architecture and, thanks to the efforts of many expert people and some of our expertise, we have set up a full-system fuzzer for Apple’s iOS.

The skill set we have learned in this chapter are the final steps toward creating a full-system emulation. These skills involve creating a way to send AFL input to an emulated system, using functions such as dup2() to establish communication channels. We also learned how to create a way to stop a VM and retrieve input using hypercalls and free interrupt handlers to capture relevant information. Additionally, we utilized an interface to enumerate all the system calls and tested them through a loop, employing techniques such as the __syscall assembly trick. Finally, we learned how to put everything together in an unknown and closed source architecture, integrating the various components and techniques to emulate the system effectively...