No Public Ingress Sgr

Security groups should not allow unrestricted ingress to SSH or RDP from any IP address.

Security groups provide stateful filtering of ingress and egress network traffic to AWS resources. It is recommended that no security group allows unrestricted ingress access to remote server administration ports, such as SSH to port 22 and RDP to port 3389.

Impact

Recommended Actions

Follow the appropriate remediation steps below to resolve the issue.

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Resources:
  GoodSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Limits security group egress traffic
      SecurityGroupIngress:
        - CidrIp: 127.0.0.1/32
          IpProtocol: "6"
          FromPort: 22
          ToPort: 22

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resource "aws_security_group_rule" "good_example" {
  type        = "ingress"
  cidr_blocks = ["10.0.0.0/16"]
}

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resource "aws_security_group_rule" "example" {
  type              = "ingress"
  security_group_id = "sg-123456"
  from_port         = 22
  to_port           = 22
  protocol          = "tcp"
  cidr_blocks = [
    "1.2.3.4/32",
    "4.5.6.7/32",
  ]
}

Links

• https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/security-group-rules-reference.html

• https://docs.aws.amazon.com/securityhub/latest/userguide/ec2-controls.html#ec2-13

• https://docs.aws.amazon.com/securityhub/latest/userguide/ec2-controls.html#ec2-14