CI/CD Security Audit — GitHub Actions

The same handful of workflow bugs accounts for most GitHub Actions compromises — a tag-pinned action gets re-pointed at malicious code, a PR title lands in a run: block, pull_request_target checks out the head SHA with secrets in scope. This skill finds all of them in one pass and hands back a triaged, file:line fix list.

The agent runs a bundled, zero-dependency Node script over .github/workflows/*.yml and turns the JSON report into a hardening plan.

DETECTS (fail severity)

• script-injection — attacker-controlled github.event.* fields (PR/issue titles and bodies, comments, reviews, head_ref, commit messages) interpolated into run blocks
• pull-request-target-checkout — ref: github.event.pull_request.head.sha under pull_request_target — the textbook CI RCE
• permissions-write-all — every scope granted to GITHUB_TOKEN
• unpinned-action — uses: with no version ref at all

DETECTS (warn severity)

• unpinned-action — uses: pinned to a mutable tag/branch instead of a full commit SHA; docker:// images without a @sha256: digest
• pull_request_target trigger present
• permissions-missing — no permissions: block declared
• permissions-broad-write — contents: write / id-token: write
• secret-in-run — ${{ secrets.* }} interpolated directly in run/echo lines

OUTPUT JSON on stdout: findings[] with id, severity, file, line, detail, recommendation, plus a summary with fail/warn counts and byId breakdown. Exit 0 clean / 1 findings / 2 usage error — drop into a pre-merge check or CI job.

WHY IT'S SAFE TO RUN EVERYWHERE Pure line-based static scan: reads .yml/.yaml only, zero npm dependencies, no network calls, never executes a line of workflow code. Node 18+.

HONEST ABOUT LIMITS A line-based auditor can't evaluate action internals, reusable-workflow trust, environment protection rules, or org/enterprise token defaults. The skill's triage guide says exactly what was and wasn't checked — clean means "no known patterns matched", not "secure".

Includes a triage playbook per finding ID and an optional CI-gate recipe (fail the pipeline on summary.fail > 0).