chore(skills): improve vulnerability-remediation skill

Signed-off-by: Miguel Martinez <miguel@chainloop.dev>

Author: migmartri

.claude/skills/vulnerability-remediation/SKILL.md

@@ -0,0 +1,199 @@
+---
+name: vulnerability-remediation
+description: Reviews vulnerability policy violations for the chainloop project recorded in Chainloop and performs fixes in Dockerfiles or go.mod. Use when asked to fix vulnerabilities, review CVEs, or remediate security issues in chainloop.
+---
+
+# Vulnerability Remediation for chainloop
+
+This skill reviews open vulnerability policy violations recorded in Chainloop for the `chainloop` project and applies fixes to the affected source files.
+
+## Step 1: Find the Latest Project Version
+
+Use `list_products_with_versions` (no parameters needed — uses the current `chainloop` org) and locate the **Chainloop Community Edition** product. Find the `chainloop` project version entry and note its `projectVersionId` (UUID).
+
+## Step 2: Gather Compliance Results and Evidence in Parallel
+
+Once the `projectVersionId` is known, make both of these calls **at the same time**:
+
+**Call A** — `get_frameworks_compliance`:
+- `project_version_id`: the UUID from Step 1
+- `framework_ids`: `["0ceef195-6900-4166-8407-77eb84954ed3"]` (chainloop-best-practices)
+
+**Call B** — `list_pieces_of_evidence`:
+- `project_name`: `chainloop`
+- `project_version_name`: the version name from Step 1 (e.g. `v1.77.0`)
+- `latest`: `true`
+
+### Parsing the compliance result (Call A)
+
+The response will be large — parse it programmatically using a Bash subagent:
+
+```python
+import json
+
+with open('<tool-result-file>') as f:
+    raw = json.load(f)
+data = json.loads(raw[0]['text'])
+
+for req in data:
+    if 'vulnerabilit' in req.get('name', '').lower():
+        status = req.get('status', '')
+        failed = [e for e in req.get('policyEvaluations', [])
+                  if e.get('status') not in ('PASSED', 'SKIPPED')]
+        print(f"Requirement: {req['name']} — Status: {status}")
+        for e in failed:
+            print(f"  FAILED: policy={e['name']} material={e.get('materialName','-')} status={e.get('status','-')}")
+```
+
+This gives you the list of **failing material names** (e.g. `control-plane-migrations-report`).
+
+## Step 3: Download the SARIF for Each Failing Material
+
+From the `list_pieces_of_evidence` result (Call B above), find the item whose `name` matches the failing material name and whose `kind` is `SARIF`. Use its `digest` field directly — no need to decode attestations.
+
+Call `download_evidence_by_digest` with:
+- `digest`: the digest of the matching SARIF item
+- `download_content`: `true`
+
+The SARIF `logicalLocations[].fullyQualifiedName` field contains the full image reference, e.g.:
+```
+ghcr.io/chainloop-dev/chainloop/control-plane-migrations:v1.77.0@sha256:<digest>:/atlas
+```
+
+The binary path (e.g. `/atlas`, `/app`) tells you which binary inside the image is vulnerable.
+
+## Step 4: Identify the Fix
+
+### 4a. Atlas / Migration Dockerfile vulnerabilities
+
+**Symptom**: SARIF location is `/atlas`, image is `control-plane-migrations`
+
+**Source file**: `app/controlplane/Dockerfile.migrations`
+
+**Fix procedure**:
+1. Check the current atlas version in the comment at the top of the Dockerfile (e.g. `# atlas version v1.1.0`)
+2. Find the latest available version:
+   ```bash
+   curl -s "https://registry.hub.docker.com/v2/repositories/arigaio/atlas/tags?page_size=20&ordering=last_updated" \
+     | python3 -c "import json,sys; [print(t['name']) for t in json.load(sys.stdin)['results'] if t['name'][0].isdigit() and '-' not in t['name']]"
+   ```
+3. Run grype on the current and candidate versions to confirm the CVEs are present then gone:
+   ```bash
+   grype arigaio/atlas:<current-version> --only-fixed 2>&1
+   grype arigaio/atlas:<new-version> --only-fixed 2>&1
+   ```
+   A clean run has only the header line and no CVE rows.
+4. Once a clean version is confirmed, pull it and get its digest:
+   ```bash
+   docker pull arigaio/atlas:<new-version>
+   docker inspect --format='{{index .RepoDigests 0}}' arigaio/atlas:<new-version>
+   ```
+5. Update `app/controlplane/Dockerfile.migrations`:
+   ```dockerfile
+   # from: arigaio/atlas:<NEW_VERSION>
+   # docker run arigaio/atlas@sha256:<NEW_DIGEST> version
+   # atlas version v<NEW_VERSION>
+   FROM arigaio/atlas@sha256:<NEW_DIGEST> as base
+   ```
+
+### 4b. Go stdlib / Go module vulnerabilities (backend)
+
+**Symptom**: SARIF location is a Go binary (e.g. `/app`, `/server`), package is `stdlib` or a Go module
+
+**Fix options** (in order of preference):
+
+**Option A — Upgrade Go version** (for stdlib CVEs):
+Use the `upgrading-golang` skill to bump the Go version in `go.mod` and all Dockerfiles.
+
+**Option B — Upgrade a specific Go dependency** (for third-party modules):
+1. Identify the affected module from the SARIF `purls` field (e.g. `pkg:golang/github.com/foo/bar@v1.2.3`)
+2. Update `go.mod`:
+   ```bash
+   go get github.com/foo/bar@<fixed-version>
+   go mod tidy
+   ```
+3. Verify with grype:
+   ```bash
+   grype dir:. --only-fixed 2>&1
+   ```
+
+## Step 5: Verify the Fix with Grype
+
+Always run grype before and after the change to confirm the CVEs are resolved:
+
+```bash
+# Before — should show the CVE rows
+grype <image>:<current-version> --only-fixed 2>&1
+
+# After — should show header only, no CVE rows
+grype <image>:<new-version> --only-fixed 2>&1
+```
+
+A clean run has only the column header line and zero data rows.
+
+## Step 6: Commit and Create a PR
+
+1. Check which branch you are on — do **not** create a new branch if one already exists:
+   ```bash
+   git branch --show-current
+   ```
+
+2. Commit with signoff (no co-author):
+   ```bash
+   git add <changed-files>
+   git commit -s -m "fix(<scope>): <short description of the CVE fix>"
+   git push -u origin <current-branch>
+   ```
+
+3. Create the PR with `gh pr create`:
+   ```bash
+   gh pr create --title "fix(<scope>): <short description>" --body "$(cat <<'EOF'
+   ## Summary
+
+   - <bullet: what was upgraded and why>
+   - Fixes <CVE-ID> (<Severity>) and <CVE-ID> (<Severity>) in <package>
+   - <brief note on how the fix works, e.g. new version built with Go X.Y.Z>
+   EOF
+   )"
+   ```
+
+## Step 7: Report Results
+
+Summarise the findings and changes in this format:
+
+```
+## Vulnerability Remediation Summary
+
+**Project**: chainloop v<version>
+**Requirement**: no-vulnerabilities-high — was: FAIL
+
+### Fixed
+
+| CVE | Severity | Package | Old Version | Fix Applied |
+|-----|----------|---------|-------------|-------------|
+| CVE-XXXX-XXXXX | Critical | <pkg> | <old> | Upgraded <file> to <new> |
+
+### Files Changed
+- `app/controlplane/Dockerfile.migrations` — atlas vX.X.X → vX.X.X
+
+### PR
+<GitHub PR URL>
+```
+
+## Key Reference Data
+
+| Item | Value |
+|------|-------|
+| Chainloop org | `chainloop` |
+| Project name | `chainloop` |
+| chainloop-best-practices framework ID | `0ceef195-6900-4166-8407-77eb84954ed3` |
+| Continuous-scanning workflow ID | `c506a425-d307-4a59-9132-659ffd417b57` |
+| Migrations Dockerfile | `app/controlplane/Dockerfile.migrations` |
+| Backend go.mod | `go.mod` (root) |
+
+## Important Notes
+
+- Always pin Docker images by SHA256 digest, not tag alone
+- For Go stdlib CVEs, upgrading the atlas or golang builder image is usually sufficient — check via grype before touching go.mod
+- Run `go mod tidy` after any go.mod change
+- The compliance-scanning runs daily, so the policy status will update automatically after the fix is merged and a new image is built