How to secure your web application — a practical guide for developers Focused web application security is about reducing attack surface, validating trust boundaries, and assuming all external input is hostile. The OWASP Top Ten provides a practical map of the most common risks. This guide walks through the core vulnerabilities-XSS, CSRF, SQL injection, authentication and authorization flaws-and shows how to prevent them using modern patterns like secure headers, HTTPS, CSP, cookies, dependency scanning, and input validation. Understanding the OWASP Top Ten The OWASP Top Ten highlights categories such as broken access control, cryptographic failures, injection, insecure design, and security misconfiguration. Rather than memorizing the list, treat it as a checklist of failure modes: Input is not validated or encoded. Identity is not strongly verified. Permissions are not enforced server-side. Secrets and data are exposed in transit or at rest. Dependencies introduce known vulnerabilities.…