Jazzer vs Netzob

Jazzer is a free, coverage-guided fuzzer for JVM applications, running in-process and based on libFuzzer. It supports Java, Kotlin, Scala, and Clojure targets, as well as JNI and native libraries. With JUnit 5.9.0 or newer, fuzz tests can run alongside regular unit tests. The @FuzzTest annotation lets Jazzer generate and mutate method inputs, including primitives, strings, arrays, and standard library classes. JUnit fuzz tests can use saved crashing inputs in regression mode or generate and mutate inputs to explore coverage. Built-in sanitizers detect Java security issues such as SSRF, file path traversal, and OS command injection, and provide feedback to guide fuzzing. The README documents use with Maven, Gradle, and Bazel. Jazzer can also run as a standalone binary or through its Java main class. Supported systems are Linux x86_64 and arm64, macOS 12 or newer on x86_64 and arm64, and Windows x86_64. The jazzer-junit package is available on Maven Central, and the repository identifies the project as licensed under Apache-2.0.

Netzob is a free, GPLv3-licensed open-source tool for reverse engineering, traffic generation, and fuzzing of communication protocols. It infers message formats and protocol state machines through passive and active processes. Vocabulary inference learns formats from supplied traces, while grammar inference supports semi-automatic state-machine learning. With those models, its simulator can act as a client, server, or both to generate traffic. The fuzzing module creates optimized test cases by mutation or generation. Inputs can include live network traffic, PCAP captures, IPC, text and binary files, and API flows through supported formats. Exports include XML, human-readable output, and Peach fuzzer formats, with custom exporters possible. Netzob runs locally on Linux and Windows and supports Python 3. It targets network protocols, structured files, text protocols, drivers, devices, and other listed target types. Version 0.4.1 is listed as the latest stable release, with packages dated February 2, 2013.