Implementing Secure Coding Patterns

Modern web frameworks provide built-in XSS protections, but developers must understand how to use them correctly. Template engines in frameworks like React, Angular, and Vue.js automatically encode output by default, but they also provide "dangerous" methods for inserting raw HTML when needed. These dangerous methods (like React's dangerouslySetInnerHTML or Angular's innerHTML binding) should be used sparingly and only with thoroughly sanitized content.

When frameworks' built-in protections aren't sufficient, implement additional security layers. Create secure wrapper functions for common operations that ensure proper encoding. For example, instead of directly using innerHTML, create a function that sanitizes input using a library like DOMPurify before insertion. Centralize these security functions to ensure consistent application across your codebase and make security updates easier. Regular code reviews should specifically check for uses of dangerous functions and ensure they're properly protected.

Adopt secure coding patterns that make XSS prevention the default rather than requiring developers to remember security measures. Use Content Security Policy headers to provide defense-in-depth. Implement automatic security scanning in your CI/CD pipeline to catch vulnerabilities before deployment. Create secure-by-default components that teammates can use without worrying about XSS. For example, a secure comment component that handles all necessary encoding and sanitization internally.