S3 is considered to be secure by default. A new object will have no access except for the account owner. An account owner of an S3 resource is the account that created that resource.
Let's go through some important concepts related to ACLs:
- ACLs provide basic read/write permission to buckets, objects, and their ACLs.
- ACLs can only grant access to AWS accounts and predefined groups.
- ACLs, by default, allow full control to the owner of the resource and nothing to everyone else.
- ACLs can only grant permission; they cannot deny access.
- ACLs are represented internally as XML documents.
- ACLs are generally considered legacy and, wherever possible, it is preferable to use either an IAM policy or a bucket policy. However, there ...