Security Audit: Hardening Node.js Applications

OWASP Top 10 Protections

1. Timing Attack Protection: Use crypto.timingSafeEqual for secret and hash comparisons.
2. ReDoS (Regular Expression Denial of Service): Avoid nested quantifiers; enforce regex execution timeouts.
3. Prototype Pollution: Freeze base prototypes and validate JSON schema structures using Zod.
4. Header Hardening: Use helmet to inject strict CSP, HSTS, and frameguard headers.