cloudflare/security-audit-skill

What it does

The parent runs validate-coverage-ledger.cjs after creating the ledger and after each later ledger update. It runs validate-findings.cjs in Phase 4 and again after every Phase 5 replacement.

The verdicts are distinct: confirmed has a complete source trace and bounded observed result, needsvalidation has an exact unresolved fact and no severity, and rejected records a disproved candidate.

Multiple runs against the same repo are additive. The skill uses prior ledgers and findings to target gaps, revalidate changed source, and carry forward current-source evidence without treating stale or unresolved work as covered.

• Reconnaissance -- map architecture, trust boundaries, input surfaces, prior evidence, and deterministic coverage in architecture.md and coverage-ledger.json.
• Coverage-led hunting -- assign isolated hunters from ledger units, record their checks, and use coverage critics to find gaps.
• Candidate validation -- give every unique candidate to a fresh verifier that tries to disprove it.
• Structured output -- write confirmed, needsvalidation, and rejected records to findings.json and validate them against report-schema.json.
• Independent record verification -- fresh agents verify final source claims. Material replacements receive another independent verifier.
• Target-neutral reporting -- derive REPORT.md, FINDINGS-DETAIL.md, and NEEDS-VALIDATION.md from the verified records and coverage ledger.

Installation

Run npx skills --help for agent-selection and non-interactive options.

npx skills add https://github.com/cloudflare/security-audit-skill \
  --skill security-audit

Usage

Start your coding agent in (or pointed at) the codebase you want to audit, then ask it to do a security audit:

The skill activates automatically when the request matches its trigger (security audit, find vulnerabilities, pen-test the code, etc.). A direct codebase audit or pen-test request uses full audit mode. Security questions and focused vulnerability work use guidance mode unless you request report artifacts. In full audit mode, an unspecified output directory defaults to ~/security-audit-skill//run-. The workflow writes inside the target repository only when you explicitly select a directory that version control ignores.

security audit this codebase

Requirements

• A coding agent with a model that supports tool use and parallel sub-agents
• Node.js for the zero-dependency findings and coverage-ledger validators
• An OS-enforced sandbox for target-controlled builds, tests, processes, browsers, emulators, fuzzers, and fixtures. It must disable external networking, use a sanitized allowlisted environment, enforce

Design principles

• Only confirm established boundary failures. Keep a source-grounded blocked lead as needsvalidation with its exact unresolved fact.
• Adversarial validation. The agent that checks a finding is never the agent that found it.
• Severity requires impact. Likelihood x impact, not deviation from a checklist.
• Defense-in-depth gaps are not vulnerabilities. If Layer A prevents the attack, the absence of Layer B is a hardening note.
• Multiple runs improve coverage. In our test runs, a single run found roughly half of the vulnerabilities that repeated runs found in total.

Files

• SKILL.md — Setup, core principles, platform terminology, workflow overview, and audit anti-patterns
• RECONNAISSANCE.md — Phase 1 reconnaissance prompts and synthesis instructions
• HUNTING.md — Phase 2 orchestration, hunting methodology, and validation rules
• ATTACK-CLASSES.md — Core, wildcard, and obvious-things attack prompts
• MEMORY-SAFETY-AND-BINARY.md — Memory-safety, binary, and kernel hunting classes for native targets
• AI-AND-LLM.md — Prompt-injection, agent/tool, and output-handling hunting classes for LLM-backed targets
• WEB-PROTOCOL-AND-AUTH.md — HTTP request-framing, cache, and authentication-protocol hunting classes for HTTP-protocol and auth targets
• CLIENT-SIDE.md — DOM-injection, messaging-trust, UI-redress, and prototype-pollution hunting classes for client-side/browser targets
• SUPPLY-CHAIN-AND-RELEASE.md — Dependency, CI, release, signing, update, plugin, and extension hunting classes
• CLOUD-AND-DEPLOYMENT.md — IAM, infrastructure-as-code, container, serverless, ingress, and runtime-configuration hunting classes
• PROTOCOLS-RPC-AND-MESSAGING.md — RPC, serialization, queue, broker, webhook, and streaming-protocol hunting classes
• RESOURCE-EXHAUSTION-AND-AVAILABILITY.md — Shared resource, quota, queue, worker, and operator-spend hunting classes
• DATA-ISOLATION-AND-LIFECYCLE.md — Tenant isolation, cache, search, export, backup, migration, deletion, and restore hunting classes
• DESKTOP-MOBILE-AND-LOCAL-IPC.md — Native app, deep-link, webview, exported-component, helper, daemon, and local-IPC hunting classes