What are CORS headers and how do they work?

What are CORS headers and how do they work?

CORS stands for Cross-Origin Resource Sharing. It's a security feature that allows or restricts resources requested from another domain. CORS headers are used by the server to indicate whether the requested resource can be shared with the requesting origin.

What issues can arise from CORS headers?

Common issues include 'No 'Access-Control-Allow-Origin' header is present' errors, which occur when the server doesn't allow requests from the origin, and misconfigured headers that can lead to security vulnerabilities.

How can I fix CORS issues in my application?

To fix CORS issues, ensure your server is configured to include the appropriate 'Access-Control-Allow-Origin' header. You can also use middleware in frameworks like Express to handle CORS.

Are there any tools to help debug CORS issues?

Yes, tools like Postman and browser developer tools can help you inspect CORS headers and troubleshoot issues.