Security headers guide
Security headers greatly reduce injection, clickjacking, and information leakage risks.
Why these headers really matter
Modern web attacks often exploit permissive configurations. Security headers act as guardrails and reduce the impact of inevitable application mistakes.
- CSP: controls allowed sources for scripts and styles.
- HSTS: forces HTTPS to prevent downgrade attacks.
- X-Frame-Options: limits clickjacking through iframes.
- X-Content-Type-Options: prevents MIME sniffing.
MVP implementation checklist
- Enable HSTS only after verifying full HTTPS coverage.
- Start CSP in report-only mode, then tighten allowed sources gradually.
- Block framing by default with X-Frame-Options or frame-ancestors.
- Re-check headers after every frontend/backend release.
FAQ
Which header is the best first step?
CSP is often the most impactful, but HSTS and X-Frame-Options provide fast wins with simple rollout.
Can CSP break my site?
Yes if tightened too quickly. Use report-only first, fix legitimate violations, then switch to blocking mode.