🔒 Protect against Stored, Reflected and DOM-Based XSS attacks

[JamesAlfonse]

Ensure that code is protected against cross-site scripting attacks.

1. Input Validation: Validate and sanitize all suer inputs to ensure they don’t contain malicious scripts.
2. Output Encoding: Encode data before reflecting it back to the user to prevent the browser from executing it as code.
3. Use Security Headers: Implement Content Security Policy (CSP) to restrict the sources of executable scripts.
4. Secure Javascript Code: Avoid using functions that directly insert user input into the DOM, such as innerHTML
5. Use Safe Methods: Use safe methods like textContent or setAttribute that don’t execute scripts.
6. Regular Code Reviews: Review client-side code regularly to identify and fix vulnerabilities.
7. Escape user inputs in your code to ensure they are treated as data, not code.
8. Utilize security libraries and frameworks that have built-in protections against XSS.
9. Implement proper authentication and authorization to control who can submit content.
10. Regularly update and patch your systems and dependencies to fix known vulnerabilities.
11. Conduct regular security testing and code reviews to identify and fix potential XSS flaws.
12. Limit data storage and permissions to minimize the impact of any potential attack.
13. Educate your development team on secure coding practices and XSS prevention techniques.