Web Security Essentials: Protecting Your Applications

Security is not optional. This comprehensive guide covers the essential security practices every web developer must implement to protect their applications and users.

Content Security Policy (CSP) Implementation

// Express.js middleware for comprehensive security headers
import helmet from "helmet";

app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      scriptSrc: ["'self'", "'nonce-{random}'"],
      styleSrc: ["'self'", "'unsafe-inline'"],
      imgSrc: ["'self'", "data:", "https:"],
      connectSrc: ["'self'", "https://api.example.com"],
      fontSrc: ["'self'", "https://fonts.gstatic.com"],
      objectSrc: ["'none'"],
      upgradeInsecureRequests: [],
    },
  },
  crossOriginEmbedderPolicy: true,
  crossOriginOpenerPolicy: true,
  crossOriginResourcePolicy: { policy: "same-site" },
  referrerPolicy: { policy: "strict-origin-when-cross-origin" },
}));