ref-owasp-checklist

name	ref-owasp-checklist
description	OWASP Top 10 security checklist, authentication patterns, input validation, and HTTP security headers reference. Agent-extending skill that amplifies expert-security and expert-backend expertise with production-grade security patterns. NOT for: frontend UI, DevOps deployment, performance optimization, testing strategy.
user-invocable	false
metadata	{"version":"1.0.0","category":"domain","status":"active","updated":"2026-03-30","tags":"owasp, security, checklist, authentication, validation, reference","agent":"expert-security"}
progressive_disclosure	{"enabled":true,"level1_tokens":100,"level2_tokens":3000}
triggers	{"keywords":["owasp","security","vulnerability","injection","xss","csrf","auth"],"agents":["expert-security","expert-backend"],"phases":["run"]}

OWASP Security Checklist Reference

Target Agents

• expert-security - Primary: applies checklist during security audits
• expert-backend - Secondary: applies during API implementation

OWASP API Security Top 10

Rank	Vulnerability	Check	Defense
A1	BOLA (Broken Object Level Authorization)	Can user A access user B's resources?	Verify object ownership at every endpoint
A2	Broken Authentication	Weak passwords, unlimited login attempts?	bcrypt (cost 12+), rate limit, MFA
A3	Broken Object Property Level Authorization	Are hidden fields exposed in responses?	Response DTOs, field-level filtering
A4	Unrestricted Resource Consumption	Can mass requests crash the server?	Rate limiting, enforce pagination limits
A5	Broken Function Level Authorization	Can regular users call admin APIs?	RBAC middleware, permission checks
A6	SSRF (Server-Side Request Forgery)	Can URL input access internal resources?	URL whitelist, block internal IPs
A7	Security Misconfiguration	Debug mode, default accounts exposed?	Separate prod config, inspect headers
A8	Lack of Automated Threat Protection	Can APIs be called in abnormal sequences?	State machine validation, business rules
A9	Improper Asset Management	Unused APIs, old versions exposed?	API inventory, version deprecation
A10	Unsafe API Consumption	Are external API responses trusted blindly?	Validate external responses, set timeouts

Authentication Checklist

Password Policy

• Minimum 8 characters, show strength meter (not strict rules)
• bcrypt (cost factor 12+) or Argon2id
• Temporary lock after 5 failed attempts (15 min) or CAPTCHA
• Prevent reuse of last 5 passwords

JWT Configuration

Setting	Recommended Value
Access Token Expiry	15-30 minutes
Refresh Token Expiry	7-14 days
Algorithm	RS256 (asymmetric) or HS256
Storage	httpOnly + secure + sameSite cookie
Payload	Minimal: userId, role only (no PII)
Renewal	Silent refresh or token rotation

Session Security

• Regenerate session ID after login
• Invalidate session on logout (server-side)
• Set session timeout (30 min idle)
• Bind session to IP/User-Agent (optional, strict)

HTTP Security Headers

Header	Value	Purpose
Strict-Transport-Security	max-age=31536000; includeSubDomains	Force HTTPS
X-Content-Type-Options	nosniff	Prevent MIME sniffing
X-Frame-Options	DENY or SAMEORIGIN	Prevent clickjacking
Content-Security-Policy	default-src 'self'	Prevent XSS
Referrer-Policy	strict-origin-when-cross-origin	Limit referrer
Permissions-Policy	camera=(), microphone=()	Restrict browser features

Input Validation Checklist

Type	Method	Tool
Schema validation	Type + structure check	Zod, Joi, pydantic, Go validator
Length limits	Min/max constraints	Schema definitions
SQL Injection	Parameterized queries	ORM (Prisma, GORM, SQLAlchemy)
XSS Prevention	HTML escaping	DOMPurify (client), server escape
Path Traversal	Path normalization	filepath.Clean + whitelist
File Upload	Type + size validation	MIME type + magic number check
CORS	Origin whitelist	Never origin: '*' with credentials

Sensitive Data Handling

Data Type	Storage	Transmission	Logging
Passwords	bcrypt hash only	HTTPS only	NEVER
API Keys	Environment variables	Header (Authorization)	Masked (first 4 chars)
PII	Encrypted (AES-256)	HTTPS only	Masked
Credit Cards	Tokenized (payment provider)	Provider SDK	NEVER
Sessions	httpOnly cookie	HTTPS only	NEVER

Security Review Severity Levels

Level	Label	Action	Example
P0	CRITICAL	Block release	SQL injection, auth bypass
P1	HIGH	Fix before merge	Missing authorization check
P2	MEDIUM	Fix within sprint	Weak password policy
P3	LOW	Track in backlog	Missing security header

Common Rationalizations

Rationalization	Reality
"This is an internal application, OWASP does not apply"	Internal applications are reachable from compromised internal services. OWASP applies to all web applications.
"The framework handles XSS protection"	Frameworks protect default rendering paths. Dynamic HTML insertion, innerHTML, and template literals bypass the protection.
"We do not store sensitive data, so encryption is unnecessary"	Session tokens, API keys, and PII are sensitive data. If the application has users, it has sensitive data.
"Security headers are just defense-in-depth, not critical"	Each security header blocks a specific attack class. Missing CSP enables XSS even when output is escaped.
"I will do a security review before release"	Late security reviews find issues that are expensive to fix. Secure coding practices prevent them from the start.

Red Flags

• User input rendered in HTML without escaping or sanitization
• SQL query built with string concatenation instead of parameterized queries
• Authentication token stored in localStorage instead of httpOnly cookie
• Missing Content-Security-Policy header on response
• Secrets (API keys, passwords) found in source code or configuration files committed to git

Verification

• OWASP Top 10 checklist reviewed for the change (show which items were evaluated)
• User input sanitized before rendering in HTML output
• All database queries use parameterized statements
• Security headers present (CSP, X-Frame-Options, X-Content-Type-Options)
• No secrets found in source code (show grep results for common secret patterns)
• Authentication tokens use httpOnly, Secure, SameSite cookie attributes