Integrate libFuzzer with Vulnetix. Write fuzz targets compiled with -fsanitize=fuzzer, run them to discover crashes, and convert findings to JSON.
Install & scan
$ # Ubuntu/Debian sudo apt-get install clang llvm # macOS via Homebrew brew install llvm # Verify: libFuzzer is part of clang clang -fsanitize=fuzzer empty.c -o test && echo "libFuzzer available" $ # Compile the fuzz target clang++ -g -fsanitize=fuzzer,address fuzz_target.cc -o fuzz_target # Run the fuzzer ./fuzz_target -max_total_time=300 corpus/
Run libFuzzer in CI
Scan on every push and upload the report as a workflow artifact:
- name: Install Clang
run: sudo apt-get install -y clang
- name: Build fuzz target
run: clang++ -g -fsanitize=fuzzer,address fuzz_target.cc -o fuzz_target
- name: Run libFuzzer (2 minutes)
run: |
timeout 120 ./fuzz_target -max_total_time=120 corpus/ || true
ls crash-* 2>/dev/null && echo "Crashes found!" || echo "No crashes"
How Vulnetix compares: better together
Vulnetix does not replace libFuzzer. Keep running it. Vulnetix sits on top of libFuzzer (and every other scanner you already own) turning disconnected tool outputs into one prioritised, fixable queue.
| Capability | Vulnetix | libFuzzer |
|---|---|---|
| Security coverage | ||
| SAST (static code analysis) | ✓ Built-in rules + Semgrep augmentation | ✗ |
| SCA / dependencies | ✓ 40+ ecosystems, transitive graph | ✗ |
| DAST (dynamic testing) | ~ Ingests DAST results; no native dynamic engine | ✗ |
| Container & image | ✓ Image CVEs, base image, Dockerfile | ✗ |
| IaC / misconfiguration | ✓ Terraform, k8s, CloudFormation | ✗ |
| Secret scanning | ✓ 1,000+ rules, source + binary + git history | ✗ |
| Cloud / CSPM | ✓ Cloud-posture findings, compliance tab | ✗ |
| Mobile (MAST) | ~ Ingests mobile scanner output; no native mobile engine | ✗ |
| License compliance | ✓ SPDX, copyleft/AGPL/SSPL policy | ✗ |
| SBOM generation | ✓ CycloneDX 1.7 + SPDX 2.3, cosign-signable | ✗ |
| Malware / supply-chain | ✓ De-duplicated corpus + install-time firewall (25+ registries) | ✗ |
| Network / infra vuln | ~ Ingests network scanner output; no native network scanner | ✗ |
| Fuzzing | ✗ Ingests fuzzing crashes; no native fuzzer | ✓ LLVM in-process coverage-guided fuzzing engine built into Clang; its sole function. |
| Pentest / bug bounty | ✗ Ingests pentest/bug-bounty findings; not a testing service | ✗ |
| The Vulnetix orchestration layer | ||
| Cross-scanner dedup & one queue (ASPM) | ✓ Correlates every scanner into one prioritised queue with ownership routing | ✗ |
| Exploit-intel prioritisation | ✓ EPSS, CISA KEV, Coalition ESS, CWSS, Vulnetix LEV | ✗ |
| Reachability analysis | ✓ Tree-sitter + CVEAffected; direct/transitive/semantic | ✗ |
| Versioned VEX + audit trail | ✓ Immutable OpenVEX/CycloneDX, cosign-signable | ✗ |
| Safe Harbour autofix | ✓ Resolves + applies the nearest safe version | ✗ |
| End-of-life policy | ✓ Flags/blocks past-EOL runtimes & packages | ✗ |
| SSVC / risk-based policy | ✓ SSVC v2 + CISA/FedRAMP/Essential-8 presets | ✗ |
✓ full · ~ partial · ✗ not covered
What libFuzzer does well
- In-process, coverage-guided fuzzing that calls the target function directly in a loop, giving very high iteration speed for targets with expensive initialization
- First-class Clang/LLVM integration via SanitizerCoverage plus ASAN/MSAN/UBSAN, catching memory corruption, use-after-free, uninitialized reads and undefined behavior
- Simple, standardized fuzz-target contract (LLVMFuzzerTestOneInput) that has become the de facto harness format reused by OSS-Fuzz and other engines
- Built-in corpus management including seed loading and corpus minimization via -merge=1
Where Vulnetix adds to it: Vulnetix has no native fuzzing engine and does not run libFuzzer; it ingests and orchestrates libFuzzer crash reports and consolidates them with scanner findings into a single prioritised, deduplicated queue enriched with exploit intelligence, reachability and versioned VEX. Better together: libFuzzer finds the bug, Vulnetix routes and governs remediation.
No migration, no rip-and-replace. libFuzzer keeps doing what it does best; Vulnetix adds the orchestration, exploit-intelligence prioritisation and remediation layer built for the way AppSec works today.
Centralise libFuzzer results in Vulnetix
Upload libFuzzer JSON output to the Vulnetix platform to deduplicate findings, prioritise them with EPSS, CISA KEV and Coalition ESS exploit intelligence, and track remediation across every scanner in a single queue.