security-scan

name: security-scan description: > Deep security scanning for .NET applications across 6 layers: vulnerable packages, secrets detection, OWASP code patterns, auth configuration, CORS policy, and data protection. Produces severity-rated findings with specific remediation steps. Load this skill when: "security scan", "security audit", "check for vulnerabilities", "find secrets", "OWASP", "auth review", "CORS check", "security review", "penetration test prep", "CVE check", "vulnerability scan", "hardcoded password", "data protection", "security posture".

/security-scan — 6-Layer Security Pipeline

What

Runs a defense-in-depth static scan across 6 layers. A project with zero CVEs can still have hardcoded secrets, SQL injection, and missing auth — each layer catches a different vulnerability class. Findings map to the OWASP Top 10:2025 taxonomy and are rated Critical/High/Medium/Low by exploitability, impact, and exposure — a Critical SQL injection on a public endpoint outranks a Low info-disclosure on an admin page.

Detection patterns, OWASP mappings, remediation code, and the report template live in references/scan-layers.md — read it before executing.

Honesty rule: this is static analysis, not a penetration test. It catches known patterns but misses business-logic flaws, complex authorization bypasses, and runtime-only vulnerabilities. Every report states this.

When

• Pre-release security gate — full scan, non-negotiable before production
• "Security scan", "security audit", "find secrets", "CVE check", "OWASP"
• After a dependency update (Layer 1), auth changes (Layer 4), config changes (Layer 2), or logging changes (Layer 6)
• Pre-pentest preparation — fix static issues before paying for a pentest
• Incident response and quarterly reviews

How

Step 1: Choose Layers

Step 2: Execute the Layers

Read references/scan-layers.md for the detection patterns per layer. Delegate deep auth and secrets review to the security-auditor agent, pairing the authentication and configuration skills.

Step 3: Rate with Context

Severity must match actual risk — over-classification causes alert fatigue and buries the real Critical:

• Test-fixture "secrets" and appsettings.Development.json values are expected — skip or mark INFO, don't flag as HIGH
• A missing XML comment is never a security finding
• Reserve Critical for exploitable-now issues: injection on public endpoints, exposed production secrets, auth bypass

Step 4: Report

Every finding: [SEVERITY] file:line — title, OWASP category, what's wrong, impact if exploited, and remediation code (before/after). Produce the summary table + per-layer status table from the reference template, prefixed with the static-analysis disclaimer.

Example

User: /security-scan before we ship

Claude: Running all 6 layers...

| Layer | Status | Findings |
|-------|--------|----------|
| 1. Packages | PASS | 0 CVEs (142 packages incl. transitive) |
| 2. Secrets | PASS | 0 real secrets (2 dev-only values skipped) |
| 3. OWASP Patterns | FAIL | 1 SQL injection |
| 4. Auth Config | WARN | 2 endpoints missing explicit auth attributes |
| 5. CORS | PASS | Explicit origins from configuration |
| 6. Data Protection | WARN | Customer email logged at Information level |

[HIGH] SearchOrders.cs:34 — SQL Injection (A05:2025)
  FromSqlRaw($"...LIKE '%{search}%'") → attacker controls the query.
  Fix: db.Orders.Where(o => EF.Functions.Like(o.Name, $"%{search}%"))

[MEDIUM] OrderEndpoints.cs:18,31 — no [Authorize]/[AllowAnonymous]; behavior
  depends on ambient global policy. Make intent explicit per endpoint.

[LOW] OrderPlacedHandler.cs:22 — PII in logs (A09:2025). Log CustomerId, not email.

Note: static analysis only — this does not replace a penetration test.

Related

• references/scan-layers.md — detection patterns, OWASP 2025 mappings, report template
• /verify — Phase 5 runs a lightweight version of this scan per change set
• /health-check — Dimension 7 (Security Posture) is the spot-check version
• authentication / configuration — remediation patterns for Layers 4 and 2