Security Issue uploading image from my web app

Question

Hi,
When I upload an image to S3 I get error in my browser:
scheme
	https
host
	sadimages.s3.eu-north-1.amazonaws.com
filename
	/dy6oisuyvixiu3tx5ybhrk7ixrfh
Address
	3.5.218.52:443
Status
403
Forbidden
VersionHTTP/1.1
Transferred298 B (0 B size)
Referrer Policystrict-origin-when-cross-origin
Request PriorityHigh
DNS ResolutionSystem

I have tried to solve this without success.
Can you help to solve this?

Regards,
Poul Erik Rasmussen

re:Post Agent · Answer

The error you're experiencing is likely related to Cross-Origin Resource Sharing (CORS) configuration or permissions issues with your S3 bucket. Here are some steps you can take to troubleshoot and resolve the issue:

1. Check your S3 bucket CORS configuration:
   Ensure that your S3 bucket has the proper CORS configuration to allow requests from your web application's origin. You should include the following in your CORS configuration:
   - AllowedOrigins: Set to your web app's domain or '*' for testing
   - AllowedMethods: Include GET, POST, PUT, DELETE, and HEAD
   - AllowedHeaders: Include '*' or specify the headers your application uses

2. Verify IAM permissions:
   Make sure the IAM user or role your application is using has the necessary permissions to upload to the S3 bucket. At minimum, you need s3:PutObject permission.

3. Check bucket policy:
   Ensure your bucket policy allows the necessary actions for your IAM user/role.

4. If using AWS Amplify:
   If you're using AWS Amplify for file uploads, make sure you've configured the Storage category correctly in your Amplify setup.

5. Verify credentials:
   Ensure that your application is using the correct AWS credentials and that they haven't expired.

6. Check for bucket encryption:
   If your bucket has default encryption enabled, make sure your IAM permissions include the ability to use the encryption key.

7. Examine CloudWatch logs:
   Check your CloudWatch logs for more detailed error messages that might provide additional insight into the issue.

If you've verified all these points and are still experiencing issues, you may need to examine your application code to ensure you're making the upload request correctly. Also, consider using the AWS CLI or SDK to test uploads directly to isolate whether the issue is with your application or the S3 configuration.  
**Sources**  
[Troubleshooting CORS - Amazon Simple Storage Service](https://docs.aws.amazon.com/AmazonS3/latest/userguide/cors-troubleshooting.html)  
[CORS error while accessing an endpoint in API gateway | AWS re:Post](https://repost.aws/questions/QUQNPMb1igReaWYfGy8k8pHg/cors-error-while-accessing-an-endpoint-in-api-gateway)  
[Access denied 403 Error while uploading to S3 bucket in production (Working locally) | AWS re:Post](https://repost.aws/questions/QUfmAN5e6kR-ataw0cyPLTJw/access-denied-403-error-while-uploading-to-s3-bucket-in-production-working-locally)  
['Network Error' uploading files with Amplify Storage | AWS re:Post](https://repost.aws/articles/ARySQq2FIUSxGR6YTrBhxDQQ/network-error-uploading-files-with-amplify-storage)

Security Issue uploading image from my web app

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