libfuzzer

SKILL.md

libFuzzer

libFuzzer is an in-process, coverage-guided fuzzer that is part of the LLVM project. It's the recommended starting point for fuzzing C/C++ projects due to its simplicity and integration with the LLVM toolchain. While libFuzzer has been in maintenance-only mode since late 2022, it is easier to install and use than its alternatives, has wide support, and will be maintained for the foreseeable future.

When to Use

Fuzzer
Best For
Complexity

libFuzzer
Quick setup, single-project fuzzing
Low

AFL++
Multi-core fuzzing, diverse mutations
Medium

LibAFL
Custom fuzzers, research projects
High

Honggfuzz
Hardware-based coverage
Medium

Choose libFuzzer when:

You need a simple, quick setup for C/C++ code

Project uses Clang for compilation

Single-core fuzzing is sufficient initially

Transitioning to AFL++ later is an option (harnesses are compatible)