HTTP Security Headers Best Practices
Hardening Web Applications with HTTP Response Headers
HTTP security headers provide a powerful layer of defense against common client-side web vulnerabilities, including Cross-Site Scripting (XSS), clickjacking, MIME-sniffing, and SSL-stripping attacks.
Core Headers Evaluated
- Strict-Transport-Security (HSTS): Enforces encrypted HTTPS connections, preventing man-in-the-middle attacks from downgrading users to unencrypted HTTP.
- Content-Security-Policy (CSP): Restricts the resources (scripts, styles, images) that the browser is allowed to load, mitigating XSS attacks.
- X-Frame-Options: Prevents your web pages from being embedded within malicious iframes on third-party sites (Clickjacking mitigation).
- X-Content-Type-Options: Setting this to
nosniffblocks browsers from attempting to guess MIME types of executable assets. - Referrer-Policy: Controls how much referrer metadata is passed along when navigating away from your site.
❓ Frequently Asked Questions
What is the HSTS Preload list?
The HSTS Preload list is a list compiled by Chrome and adopted by all major browsers. When preloaded, browsers will NEVER connect to your domain over unencrypted HTTP, even on the very first visit.