What is FuzzedDataProvider?

It is a helper class used in C++ fuzzing to easily extract structured data (like integers, floats, and strings) from a raw byte stream provided by the fuzzer.

Which languages are supported by this skill?

This skill provides specific patterns and examples for C, C++, and Rust, which are the most common languages for high-performance fuzzing.

How does this help with security audits?

It guides you in creating harnesses that reach deep code paths and handle edge cases, making it easier to discover memory corruption and logical vulnerabilities.

What is a fuzzing harness?

A harness is the entrypoint function that receives random data from a fuzzer and routes it to the system under test (SUT) to find bugs and vulnerabilities.

Can I use this for structure-aware fuzzing?

Yes, it includes patterns for using the 'arbitrary' crate in Rust and guidance for using Protocol Buffers to fuzz highly structured data formats.

Fuzzing Harness Writing

Name: Fuzzing Harness Writing
Author: trailofbits

bytrailofbits

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938

Security & Testing

Provides expert guidance and implementation patterns for creating effective fuzzing harnesses across multiple programming languages.

About

This skill empowers security researchers and developers to build high-quality fuzzing harnesses that bridge the gap between random data generation and target APIs. It offers specialized patterns for C++, Rust, and structure-aware fuzzing, ensuring high code coverage, determinism, and reproducible crash discovery. By following these established implementation patterns, users can more effectively identify memory leaks, logic errors, and security vulnerabilities in complex parsers and protocol handlers.

Key Features

Structured input extraction using FuzzedDataProvider patterns
Techniques for performance optimization and crash reproducibility
Implementation guides for interleaved and structure-aware fuzzing
938 GitHub stars
Cross-language support for C, C++, and Rust fuzzing targets
Best practices for ensuring determinism and resetting global state

Use Cases

Building a new fuzzing entry point for a complex file format parser
Converting raw byte streams into typed data for API-level security testing
Improving code coverage in an existing security audit or vulnerability research project

About

Key Features

Structured input extraction using FuzzedDataProvider patterns
Techniques for performance optimization and crash reproducibility
Implementation guides for interleaved and structure-aware fuzzing
938 GitHub stars
Cross-language support for C, C++, and Rust fuzzing targets
Best practices for ensuring determinism and resetting global state

Use Cases

Building a new fuzzing entry point for a complex file format parser
Converting raw byte streams into typed data for API-level security testing
Improving code coverage in an existing security audit or vulnerability research project