Misconfigured S3 buckets can leak private information to the entire internet or allow unauthorized data tampering / deletion.
In AWS Console -
In Terraform -
References:
https://docs.aws.amazon.com/AmazonS3/latest/userguide/s3-access-control.html
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/s3_bucket
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/s3_bucket_acl