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.

Possible Impact

The port is exposed for egressing data to the internet

Suggested Resolution

Set a more restrictive cidr range

Insecure Example

The following example will fail the aws-vpc-no-public-egress-sg check.

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

Secure Example

The following example will pass the aws-vpc-no-public-egress-sg check.

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

Getting Started
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