lcamtuf — American Fuzzy Lop (AFL) documentation (reference)
Educational routing only. This skill does not mirror the full site. Open the live pages for complete instructions, file lists, and any upstream notes.
Canonical URL
- American Fuzzy Lop (AFL) — hosted on lcamtuf.coredump.cx (Michał Zalewski’s site).
What it is
AFL is a coverage-guided fuzzer aimed primarily at C/C++ binaries via compile-time instrumentation (e.g. afl-gcc / afl-clang / LLVM modes) and the afl-fuzz driver. The published material on this site includes the original project narrative, quick-start style guidance, status screen semantics, and performance / tuning notes that many tutorials still cite.
Typical mental model for readers:
| Topic | Role |
|---|---|
| Instrumentation | Rebuild the target with AFL’s compilers/wrappers so edges are tracked. |
| Corpus & seeds | Start from small valid inputs; AFL mutates and discovers new paths. |
| Fuzzing loop | afl-fuzz runs; UI shows paths, crashes, hangs, stability—interpret per upstream docs. |
| Crashes | Triaged as potential bugs; verify, minimize, report responsibly. |
Modern fork (operational note)
Active development of the AFL lineage for many teams is AFL++ (feature-rich fork, maintained tooling). Use this skill when the user explicitly wants lcamtuf’s classic page or historical AFL terminology; use AFL++ docs for current flags, compilers, and CI integration on new projects.
How to combine with blockint
| Need | Skill |
|---|---|
| Solidity / EVM smart contract review | evm-solidity-defi-triage-agent, defi-security-audit-agent |
| Solana / Rust program security | solana-defi-vulnerability-analyst-agent, sealevel-attacks-solana |
| C/C++ native code in security research | lcamtuf-afl-documentation (AFL concepts) + project-specific build docs |
Guardrails
- Scope — Fuzz only systems you own or are explicitly authorized to test; follow program rules and laws.
- Triaging — Not every crash is exploitable; confirm with debugging and vendor disclosure practice.
- Stale tooling — Compare classic AFL behavior with current compiler and AFL++ release notes before production pipelines.
Goal: a stable pointer to lcamtuf.coredump.cx/afl for classic AFL documentation and terminology in security / fuzzing conversations.