Security is a critical aspect of modern web applications, and Angular provides built-in features to help developers protect their apps from common vulnerabilities. In this blog post, we will explore the top 3 security best practices every Angular developer must follow to build secure applications.
1. Prevent Cross-Site Scripting (XSS) Attacks
Cross-Site Scripting (XSS) is one of the most common security threats, where attackers inject malicious scripts into web applications. Angular helps prevent XSS attacks through its built-in DOM sanitization mechanisms.
How to Prevent XSS in Angular:
- Avoid using innerHTML, document.write(), or eval().
- Use Angular’s built-in sanitization to automatically escape malicious content.
- Leverage the DomSanitizer service only when absolutely necessary to safely handle dynamic HTML, styles, URLs, and scripts.
Learn more about Angular Security in the official documentation
Example: Avoid this unsafe approach:
<div [innerHTML]=”userInput”></div>
Instead, use Angular’s sanitizer:
import { DomSanitizer, SafeHtml } from ‘@angular/platform-browser’;
constructor(private sanitizer: DomSanitizer) {}
sanitizeContent(content: string): SafeHtml {
return this.sanitizer.bypassSecurityTrustHtml(content);
}
2. Secure Authentication & Authorization
Proper authentication and authorization ensure that only legitimate users can access sensitive parts of your application.
Best Practices for Authentication & Authorization:
- Use JWT (JSON Web Tokens) or OAuth for authentication.
- Implement route guards (CanActivate, CanLoad) to restrict access to protected pages.
- Never store sensitive data (such as JWT tokens or API keys) in localStorage or sessionStorage. Instead, use HTTP-only cookies for enhanced security.
Read about implementing authentication in Angular
Example: Implementing Route Guards
import { Injectable } from ‘@angular/core’;
import { CanActivate, Router } from ‘@angular/router’;
import { AuthService } from ‘./auth.service’;
@Injectable({ providedIn: ‘root’ })
export class AuthGuard implements CanActivate {
constructor(private authService: AuthService, private router: Router) {}
canActivate(): boolean {
if (this.authService.isAuthenticated()) {
return true;
}
this.router.navigate([‘/login’]);
return false;
}
}
3. Enable Content Security Policy (CSP) & HTTPS
To prevent data interception and XSS attacks, it is essential to enforce Content Security Policy (CSP) and ensure your app runs over HTTPS.
How to Implement CSP and HTTPS:
- Set CSP headers to restrict the sources of scripts and styles.
- Ensure that all API requests and assets are loaded over HTTPS to prevent Man-in-the-Middle (MITM) attacks.
- Regularly audit dependencies for vulnerabilities using tools like npm audit.
Check out security best practices in Angular
Example: Setting CSP Headers in an Express.js Backend:
app.use((req, res, next) => {
res.setHeader(“Content-Security-Policy”, “default-src ‘self’; script-src ‘self’ https://apis.google.com”);
next();
});
Conclusion
By following these three key Angular security best practices, you can significantly reduce vulnerabilities in your applications:
- Prevent XSS attacks using Angular’s built-in security mechanisms.
- Secure authentication & authorization with JWT, OAuth, and route guards.
- Enforce CSP and HTTPS to protect against malicious scripts and data interception.
Security should be an ongoing priority—regularly review and update your application’s security measures to stay ahead of potential threats. Happy coding! 🚀