Netzob
netzob.org
What it is
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.
Spec sheet
- Purpose
- Netzob is an open source tool for reverse engineering, traffic generation, and fuzzing of communication protocols.Read 7 Oct 2026 · netzob.org
- Intended users
- The overview describes Netzob as helping security evaluators create fuzzers for proprietary or undocumented protocols.Read 7 Oct 2026 · netzob.org
- Platforms
- The download page lists Debian-like packages, a Gentoo ebuild, an Arch Linux AUR package, and a Windows installer.Read 7 Oct 2026 · netzob.org
- Integrations
- The site describes export work compatible with Wireshark, Scapy, Peach, and Sulley, and the stable release changelog lists automatic Wireshark dissector and Peach fuzzer generation.Read 7 Oct 2026 · netzob.org
- Support
- The community page directs users to public announce and user mailing lists and an IRC channel for community support.Read 7 Oct 2026 · netzob.org
- License
- The site identifies Netzob as licensed under GPLv3.Read 7 Oct 2026 · netzob.org
- Exports
- The overview lists XML, human-readable, and Peach fuzzer export formats, and says users can write their own exporter.Read 7 Oct 2026 · netzob.org
- Fuzzing
- The fuzzing module uses protocol vocabulary and grammar to generate optimized test cases, with both mutation and generation available.Read 7 Oct 2026 · netzob.org
- Grammar inference
- Netzob supports semi-automatic learning of a protocol's state machine using specific algorithms.Read 7 Oct 2026 · netzob.org
- Input formats
- The overview lists live network traffic, PCAP captures, IPC, text and binary files, and API flows through supported file formats as input sources.Read 7 Oct 2026 · netzob.org
- Maintenance status
- The download page identifies version 0.4.1 as the latest stable release and dates its listed source and Debian packages to February 2, 2013.Read 7 Oct 2026 · netzob.org
- Project origin
- The overview says Netzob was initiated by security auditors at AMOSSYS and the CIDre research team of Supélec to address communication protocol reverse engineering.Read 7 Oct 2026 · netzob.org
- Protocol inference
- It can infer message formats and protocol state machines through passive and active processes.Read 7 Oct 2026 · netzob.org
- Traffic simulation
- Given inferred vocabulary and grammar models, the simulator can act as a client, server, or both to generate communication traffic.Read 7 Oct 2026 · netzob.org
- Vocabulary inference
- Its vocabulary inference learns message formats from supplied traces using specific algorithms.Read 7 Oct 2026 · netzob.org
Plans and prices
Netzob Free Open source · GNU GPLv3 Read 7 Oct 2026 · netzob.org
Strong points and limits
Strong points
- Free plan and GPLv3 license
- Infers vocabulary and protocol grammar
- Simulator acts as client, server, or both
- Mutation and generation fuzzing methods
- Exports XML and Peach formats
Limits
- Latest stable version listed is 0.4.1
- Listed packages date to February 2, 2013
- Runs only on Linux and Windows
Who it suits
Netzob suits security evaluators creating fuzzers for proprietary or undocumented protocols. It fits users working locally on Linux or Windows with Python 3 and the listed protocol or file targets.
Verdict
Netzob combines protocol inference, traffic simulation, and fuzzing in one local tool. Its old listed stable release and platform scope are important constraints to check first.
Where Specifiction places it
- Fuzz Testing Software#15 of 267.5
