fuzzing-obstacles
An agent skill by trailofbits, from trailofbits/skills. Tags: debugging, fuzzing, security, testing.
What it does
Patches past the barriers that stop a fuzzer making progress — checksum and hash verification, magic-value validation, time-based seeds, and other non-deterministic global state. Covers locating the blocking check, neutering it behind a fuzzing build flag, and avoiding the false positives a patch can introduce. Use when a fuzzer is stuck at validation, when coverage shows large regions behind a checksum, or when valid inputs are impractical to generate.
Install
With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:
npx skills add trailofbits/skills --skill fuzzing-obstaclesOr copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):
git clone --depth 1 https://github.com/trailofbits/skills
cp -r skills/plugins/testing-handbook-skills/skills/fuzzing-obstacles ~/.claude/skills/fuzzing-obstaclesSafety box score
Not rated yet. A safety box score grades what a skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. Anyone can request one from this page; it is saved for everyone. How the score works.
Source
- Repository
- trailofbits/skills (all skills from this repository)
- Path
- plugins/testing-handbook-skills/skills/fuzzing-obstacles/SKILL.md
- Branch
- main
- Collection
- testing-handbook-skills
- Updated
- 2026-09-19
Related skills
- address-sanitizer — Builds and runs code under AddressSanitizer to catch buffer overflows, use-after-free, and other memory errors during fuzzing or tests.
- atheris — Sets up and runs Atheris, the coverage-guided Python fuzzer built on libFuzzer.
- ruzzy — Sets up and runs Ruzzy, Trail of Bits' coverage-guided Ruby fuzzer and the only production-ready one for the language.
- post-patch-validation — Validates security patches with reproducible baseline-versus-patched evidence, including original exploits, root-cause variants, behavior preservation.
- aflpp — Sets up and runs AFL++ for multi-core fuzzing of C/C++ projects built with afl-clang-fast or afl-gcc-fast.
- cargo-fuzz — Sets up and runs cargo-fuzz, the standard fuzzing tool for Cargo-based Rust projects. Covers cargo fuzz init, the nightly toolchain requirement, fuzz_target!