S3 buckets should each define an aws_s3_bucket_public_access_block
Default Severity: low
Explanation
The "block public access" settings in S3 override individual policies that apply to a given bucket, meaning that all public access can be controlled in one central types for that bucket. It is therefore good practice to define these settings for each bucket in order to clearly define the public access that can be allowed for it.
Possible Impact
Public access policies may be applied to sensitive data buckets
Suggested Resolution
Define a aws_s3_bucket_public_access_block for the given bucket to control public access policies
Insecure Example
The following example will fail the aws-s3-specify-public-access-block check.
resource "aws_s3_bucket" "example" {
bucket = "example"
acl = "private-read"
}
Secure Example
The following example will pass the aws-s3-specify-public-access-block check.
resource "aws_s3_bucket" "example" {
bucket = "example"
acl = "private-read"
}
resource "aws_s3_bucket_public_access_block" "example" {
bucket = aws_s3_bucket.example.id
block_public_acls = true
block_public_policy = true
}