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

Post-crash core dump triaging

Not all crashes are equal and not all crashes are exploitable. So, how do we proceed when AFL outputs a crash? We are going to show how to triage a crash in an older version of the Linux kernel, compatible with older CVEs.

We will reuse the original crash from the TriforceAFL kernel so that it will be easier to examine crashes.

In order to prepare the environment, we need to install a few utilities. One of the most useful tools is gdb, the Linux debugger. The process of analyzing a crash is similar to debugging a program using gdb, which is the standard debugger for Linux and can be used with a core dump.

Our Triforce image, besides the original test cases, also contains their core dumps, so we can go and check them.

Our Docker image comes with gdb, the most important thing is to have a kernel with symbols. Here, we show the crash exercise. The runTest script leverages runFuzz. Hence, it keeps the same system configuration and allows us to...