HTTP Security Headers

Web application security is crucial due to evolving cyber threats, making HTTP security headers vital. These headers are response headers instructing browsers on content handling, forming a defense layer against threats like XSS and MITM attacks. They control browser behavior, enforce secure protocols, and prevent unauthorized execution. Key headers include Strict-Transport-Security (HSTS) for HTTPS enforcement and X-Content-Type-Options to prevent MIME sniffing. Referrer-Policy controls referrer information, while X-Frame-Options prevents clickjacking. Permissions-Policy manages browser feature access and Content-Security-Policy (CSP) restricts resource loading to prevent XSS. CSP Report Only is a testing version that reports violations without enforcing restrictions. Proper configuration of these headers is critical, with considerations for potential pitfalls like subdomain issues or analytics tracking. Legacy headers like X-XSS-Protection should be avoided. Regularly testing your site's security headers is advised to identify missing protections.