AFL++ vs Netzob

AFL++ is a coverage-guided fuzzer that changes input and checks whether a target binary reaches a new execution path. Its afl-cc compiler supports LTO, LLVM and GCC_PLUGIN instrumentation. The project also lists collision-free coverage, AFLfast++ power schedules, MOpt mutators, laf-intel and redqueen. Documentation covers source-available software, binary-only targets, network services and GUI programs, with build options for source-only, binary-only or combined distributions. A Docker image supports x86_64 and arm64; its example mounts target source at /src. On Linux, the installation guide recommends LLVM 18 or newer and gives LLVM 14 as the minimum. macOS build guidance covers x86_64 and arm64, but afl-clang-lto, afl-gcc-fast and qemu_mode do not work there. Fuzzing can strain hardware, consume substantial memory or disk, and create heavy filesystem activity. AFL++ is available free under AGPL terms; modified versions offered as network services must provide users the corresponding source. A commercial license is listed at €20,000 a year.

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.