EC2 instance does not expose Elasticsearch or Kibana ports

# Terraform: restrict Elasticsearch/Kibana ports to a private CIDR (not the Internet)
resource "aws_security_group" "<example_resource_name>" {
  name   = "<example_resource_name>"
  vpc_id = "<example_resource_id>"

  # CRITICAL: restrict sources; do NOT use 0.0.0.0/0 or ::/0
  ingress {
    from_port   = 9200
    to_port     = 9200
    protocol    = "tcp"
    cidr_blocks = ["10.0.0.0/8"]
  }
  ingress {
    from_port   = 9300
    to_port     = 9300
    protocol    = "tcp"
    cidr_blocks = ["10.0.0.0/8"]
  }
  ingress {
    from_port   = 5601
    to_port     = 5601
    protocol    = "tcp"
    cidr_blocks = ["10.0.0.0/8"]
  }
}

# CloudFormation: restrict Elasticsearch/Kibana ports to a private CIDR (not the Internet)
Resources:
  <example_resource_name>:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Restrict Elasticsearch/Kibana ports
      VpcId: <example_resource_id>
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 9200
          ToPort: 9200
          CidrIp: 10.0.0.0/8  # CRITICAL: do not use 0.0.0.0/0 or ::/0; restrict to internal CIDR
        - IpProtocol: tcp
          FromPort: 9300
          ToPort: 9300
          CidrIp: 10.0.0.0/8  # CRITICAL: restrict source to stop Internet exposure
        - IpProtocol: tcp
          FromPort: 5601
          ToPort: 5601
          CidrIp: 10.0.0.0/8  # CRITICAL: restrict source to stop Internet exposure