cve-scan

name	cve-scan
description	Use this skill to scan a cloned repository for a specific CVE using version-matched toolchains. Supports Go (govulncheck with GOTOOLCHAIN), Node.js (npm audit), and Python (pip-audit). Writes scan result to autofix-output/cve-scan-result.json.
allowed-tools	Bash Read Glob Write
context	fork
model	sonnet

Skill: CVE Scan

Scan a cloned repository to determine whether a specific CVE is present as an unfixed vulnerability. Uses language-appropriate scanning tools with version-matched toolchains for accurate results.

Step 1: Run the scan script

Run scripts/scan.sh which handles language detection, version-matched toolchain selection, vulnerability scanning, package version checks, and base image detection:

bash scripts/scan.sh "${REPO_DIR}" "${CVE_ID}" "${PACKAGE}" "${BUILD_LOCATION:-.}"

The script:

• Detects project language from manifest files (go.mod, package.json, requirements.txt)
• For Go: extracts the target Go version from go.mod and runs govulncheck with GOTOOLCHAIN set to that exact version, preventing false negatives from a newer local toolchain. Falls back to local toolchain if download fails.
• For Node.js: runs npm audit --json
• For Python: runs pip-audit -r requirements.txt
• If the CVE is not found in the scan, checks package manifests directly
• If the package is not in any manifest, checks Dockerfile base images
• Writes structured result to autofix-output/cve-scan-result.json

Step 2: Interpret the scan result

Read autofix-output/cve-scan-result.json and evaluate the verdict field.

Verdict	Meaning
present	CVE confirmed in scan — fix needed
present_by_version	Package in manifest at vulnerable version — fix needed
absent	Not in scan, not in manifests — VEX justification possible
in_base_image	Package not in app code, found in Dockerfile base image
informational	Go: module present but vulnerable symbol not called
scan_failed	Scanner could not run — manual review needed

Use judgment to validate the verdict:

• If present_by_version: compare the manifest version against the CVE's affected version range to confirm it is actually vulnerable
• If in_base_image: determine whether a newer base image tag is available using skopeo list-tags, or whether the base image team needs to act
• If scan_failed: check the scan_output_summary for the root cause and decide whether to retry or skip

Caller contract

The orchestrator (jira-autofix-cve-resolve) reads autofix-output/cve-scan-result.json and routes based on verdict:

• present / present_by_version → invoke /cve-fix-apply
• absent / informational → invoke /cve-vex-assess
• in_base_image → check for newer base image tag, create PR or document
• scan_failed → skip with documentation

Gotchas

• govulncheck is not installed in all environments; the script falls back to version-based detection when it is unavailable
• GOTOOLCHAIN requires a full patch version (e.g., go1.25.0, not go1.25); omitting the patch segment causes the download to fail silently
• Exit code 3 from govulncheck means "vulnerabilities found" (a successful scan), not a failure — do not treat it as an error