Public Buckets

S3 Buckets are a very useful method for data storage and file access. However, proper security restrictions need to be applied to these items in order to protect the information within. Without security settings, the public, usually in a malicious fashion to obtain sensitive information, can simply search across all open S3 items. This method is an easy win for attackers, however, it is even easier to prevent this from occurring with the correct settings. To so in S3, follow the steps provided by Amazon:

Follow these steps if you need to change the public access settings for a single S3 bucket.

To edit the block public access settings for an S3 bucket

1. Sign in to the AWS Management Console and open the Amazon S3 console at https://console.aws.amazon.com/s3/.

2. In the Bucket name list, choose the name of the bucket that you want.

1. Choose Permissions.

2. Choose Edit to change the public access settings for the bucket.

1. Choose the setting that you want to change, and then choose Save.

2. When you're asked for confirmation, enter confirm. Then choose Confirm to save your changes.

https://docs.aws.amazon.com/AmazonS3/latest/user-guide/block-public-access-bucket.html