1---
2name: application-security
3description: 'Application security covering threat modeling (STRIDE), OWASP Top 10 (2025), OWASP API Security Top 10 (2023), secure coding review, authentication/authorization patterns, input validation, encryption, security headers, supply chain security, compliance (GDPR/HIPAA/SOC2/PCI-DSS), and security monitoring. Use when reviewing code for vulnerabilities, implementing auth patterns, securing APIs, configuring security headers, hardening supply chain, preventing injection attacks, or preparing for compliance audits.'
4license: MIT
5metadata:
6 author: oakoss
7 version: '1.1'
8user-invocable: false
9---
10
11# Security
12
13Security is built-in, not bolted-on. Every feature, endpoint, and data flow must consider security implications.
14
15## OWASP Top 10 (2025)
16
17| # | Vulnerability | Prevention |
18| --- | ---------------------------------- | ----------------------------------------------- |
19| 1 | Broken Access Control | Verify permissions server-side, default deny |
20| 2 | Security Misconfiguration | Secure defaults, remove unused features |
21| 3 | Software Supply Chain Failures | SBOM, dependency scanning, signed builds |
22| 4 | Cryptographic Failures | Use TLS, hash passwords (argon2id), encrypt PII |
23| 5 | Injection | Parameterized queries, input validation |
24| 6 | Insecure Design | Threat modeling, security requirements |
25| 7 | Authentication Failures | Strong passwords, MFA, secure session mgmt |
26| 8 | Software or Data Integrity | Verify dependencies, sign releases |
27| 9 | Logging and Alerting Failures | Log security events, set up alerts |
28| 10 | Mishandling Exceptional Conditions | Fail securely, generic errors to clients |
29
30## Security Principles
31
32| Principle | Rule |
33| ------------------ | --------------------------------------------------------- |
34| Defense in Depth | Multiple layers: firewall, auth, authz, encryption, audit |
35| Least Privilege | Minimum permissions needed, nothing more |
36| Zero Trust | Never trust, always verify. Assume breach. |
37| Secure by Default | HTTPS, strict passwords, secure cookies out of the box |
38| Fail Securely | Access denied on error, no internal details to users |
39| Validate on Server | Client validation is UX, server validation is security |
40
41## Pre-Deployment Checklist
42
43| Area | Requirements |
44| ------------- | ------------------------------------------------------------------- |
45| Passwords | Hashed with argon2id (preferred) or bcrypt (12+ rounds) |
46| Tokens | JWT with EdDSA/ES256, 15min access / 7d refresh, httpOnly cookies |
47| Sessions | HttpOnly, Secure, SameSite=Strict cookies |
48| Rate Limiting | Auth endpoints: 5 attempts/15min |
49| Authorization | All routes check auth server-side, default deny |
50| Input | Validated with schema (Zod), parameterized SQL |
51| Uploads | Whitelist types, enforce size limits |
52| Secrets | No secrets in code or VCS |
53| Headers | CSP (with nonces), HSTS, Permissions-Policy, X-Content-Type-Options |
54| CORS | Configured restrictively |
55| Encryption | PII encrypted at rest (AES-256) and in transit (TLS 1.3) |
56| Logging | Audit logging for security events |
57| Dependencies | SBOM generated, `npm audit` clean, Dependabot enabled |
58
59## Threat Modeling (STRIDE)
60
61| Threat | Category | Key Mitigations |
62| ---------------------- | --------------- | ------------------------------------------------------ |
63| Spoofing | Authentication | MFA, strong passwords, JWT with short expiry |
64| Tampering | Integrity | Input validation, HTTPS/TLS, signed tokens |
65| Repudiation | Accountability | Audit logging, digital signatures |
66| Info Disclosure | Confidentiality | Encryption, least privilege, secret management |
67| Denial of Service | Availability | Rate limiting, input validation, CDN/DDoS protection |
68| Elevation of Privilege | Authorization | Authz checks on every request, ABAC, permission audits |
69
70## Risk Levels
71
72| Level | Action |
73| -------- | ------------------------- |
74| Critical | Immediate action required |
75| High | Address before launch |
76| Medium | Address post-launch |
77| Low | Monitor, may accept risk |
78
79## Compliance Overview
80
81| Framework | Scope | Key Requirements |
82| --------- | ------------------ | ------------------------------------------------------------------ |
83| GDPR | EU data subjects | Consent, data subject rights, breach notification (72h), DPIA |
84| HIPAA | US healthcare data | PHI encryption, RBAC, audit logs, BAA with providers |
85| SOC 2 | SaaS customer data | Security policies, MFA, encryption, incident response |
86| PCI-DSS | Credit card data | Use payment processor (Stripe), tokenization, network segmentation |
87
88## Anti-Patterns
89
90| Anti-Pattern | Fix |
91| --------------------------------------------- | ------------------------------------------------ |
92| Security as afterthought | Integrate from design phase |
93| Client-side authorization | Always verify permissions server-side |
94| Trusting client data (e.g., userId from body) | Get user ID from authenticated session |
95| Rolling your own crypto | Use proven libraries (argon2, bcrypt, libsodium) |
96| Compliance = security | Compliance is the minimum; security is ongoing |
97| Verbose error responses | Generic messages to clients, details server-side |
98
99## Common Mistakes
100
101| Mistake | Correct Pattern |
102| ------------------------------------------------------------- | ------------------------------------------------------------------- |
103| Performing authorization checks only on the client side | Always verify permissions server-side; client checks are UX only |
104| Trusting user-supplied IDs from request body (e.g., userId) | Derive user identity from the authenticated session or token |
105| Rolling custom cryptography instead of using proven libraries | Use argon2id, bcrypt, or libsodium for all cryptographic operations |
106| Treating compliance certification as equivalent to security | Compliance is the minimum bar; security requires ongoing review |
107| Returning verbose error messages with stack traces to clients | Show generic messages to clients; log details server-side only |
108
109## Delegation
110
111- **Scan codebase for OWASP Top 10 vulnerabilities and insecure patterns**: Use `Explore` agent to search for SQL injection, XSS, and hardcoded secrets
112- **Implement authentication, authorization, and security headers end-to-end**: Use `Task` agent to configure JWT, RBAC, CSP, HSTS, and rate limiting
113- **Design a threat model and security architecture for new features**: Use `Plan` agent to apply STRIDE methodology and map trust boundaries
114
115> For database-layer security (RLS policies, Postgres/Supabase hardening, audit trails), use the `database-security` skill. For AI/LLM security (prompt injection defense, agentic zero-trust, MCP tool hardening), use the `secure-ai` skill.
116
117## References
118
119- [Threat Modeling](references/threat-modeling.md) — STRIDE methodology, risk assessment process, trust boundaries
120- [Authentication and Authorization](references/auth.md) — JWT, session-based, OAuth, RBAC, ABAC, IDOR protection
121- [API Security](references/api-security.md) — OWASP API Security Top 10, object-level authorization, rate limiting, SSRF prevention, security testing
122- [Input Validation](references/input-validation.md) — SQL injection, XSS, command injection, path traversal, Zod validation, file upload security
123- [Data Protection](references/data-protection.md) — Password hashing (argon2id/bcrypt), AES-256-GCM encryption, secrets management
124- [Secure Configuration](references/secure-config.md) — Security headers, CORS, Express hardening, rate limiting
125- [Supply Chain Security](references/supply-chain.md) — SBOM generation, dependency scanning, CI/CD hardening, artifact signing
126- [Monitoring and Compliance](references/monitoring-compliance.md) — Audit logging, error handling, GDPR/HIPAA/SOC2/PCI-DSS, troubleshooting
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