AWS009 - An inline egress security group rule allows traffic to /0.

Explanation

Opening up ports to the public internet is generally to be avoided. You should restrict access to IP addresses or ranges that explicitly require it where possible.

Insecure Example

The following example will fail the AWS009 check.

resource "aws_security_group" "bad_example" {
	egress {
		cidr_blocks = ["0.0.0.0/0"]
	}
}

Secure Example

The following example will pass the AWS009 check.

resource "aws_security_group" "good_example" {
	egress {
		cidr_blocks = ["1.2.3.4/32"]
	}
}