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

Fuzzing Android libraries with Sloth

Android libraries that we find in our devices are compiled in the majority of the cases for ARM architectures, making it impossible to run them on a computer with an Intel architecture. Here is where our well-known tool QEMU comes in handy, but since we want to fuzz one library and not to a main binary, we will have to apply changes to QEMU’s code. In this section, we will see the project Sloth, a project for fuzzing Android’s native libraries. We will first take a look at the internals of the project, and finally, we will see how to run it in the example provided with Sloth’s source code.

Introducing Sloth's mechanisms

Sloth is a project aimed at fuzzing Android native libraries. The author of the project, as highlighted on his blog (, focused the changes applied to QEMU on the code responsible for generating the qemu-user binaries...