Vulnerable Default SSL Certificate

  • Query id: b4d9c12b-bfba-4aeb-9cb8-2358546d8041
  • Query name: Vulnerable Default SSL Certificate
  • Platform: CloudFormation
  • Severity: Medium
  • Category: Insecure Defaults
  • URL: Github

Description

CloudFront web distributions should use custom (and not default) SSL certificates. Custom SSL certificates allow only defined users to access content by using an alternate domain name instead of the default one.
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file
AWSTemplateFormatVersion: 2010-09-09
Resources:
  myDistribution:
    Type: AWS::CloudFront::Distribution
    Properties:
      DistributionConfig:
        ViewerCertificate:
          AcmCertificateArn: arn:aws:autoscaling:us-west-2:123456789012:autoScalingGroup:a1b2c3d4-5678-90ab-cdef-EXAMPLE11111
Positive test num. 2 - yaml file
AWSTemplateFormatVersion: 2010-09-09
Resources:
  myDistribution:
    Type: AWS::CloudFront::Distribution
    Properties:
      DistributionConfig:
        ViewerCertificate:
          CloudfrontDefaultCertificate: true
Positive test num. 3 - json file
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "myDistribution": {
      "Type": "AWS::CloudFront::Distribution",
      "Properties": {
        "DistributionConfig": {
          "ViewerCertificate": {
            "AcmCertificateArn": "arn:aws:autoscaling:us-west-2:123456789012:autoScalingGroup:a1b2c3d4-5678-90ab-cdef-EXAMPLE11111"
          }
        }
      }
    }
  }
}

Positive test num. 4 - json file 
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "myDistribution": {
      "Type": "AWS::CloudFront::Distribution",
      "Properties": {
        "DistributionConfig": {
          "ViewerCertificate": {
            "CloudfrontDefaultCertificate": "true"
          }
        }
      }
    }
  }
}

Code samples without security vulnerabilities

Negative test num. 1 - yaml file
AWSTemplateFormatVersion: '2010-09-09'
Resources:
  myDistribution:
    Type: 'AWS::CloudFront::Distribution'
    Properties:
      DistributionConfig:
        ViewerCertificate:
          AcmCertificateArn: arn:aws:autoscaling:us-west-2:123456789012:autoScalingGroup:a1b2c3d4-5678-90ab-cdef-EXAMPLE11111
          MinimumProtocolVersion: TLS1.2_2019
          SslSupportMethod: sni_only
Negative test num. 2 - json file
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "myDistribution": {
      "Type": "AWS::CloudFront::Distribution",
      "Properties": {
        "DistributionConfig": {
          "ViewerCertificate": {
            "AcmCertificateArn": "some arn",
            "MinimumProtocolVersion": "TLS1.2_2019",
            "SslSupportMethod": "sni_only"
          }
        }
      }
    }
  }
}
Negative test num. 3 - yaml file
AWSTemplateFormatVersion: '2010-09-09'
Resources:
  myDistribution:
    Type: AWS::CloudFront::Distribution
    Properties:
      DistributionConfig:
        Enabled: true

Negative test num. 4 - json file 
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "myDistribution": {
      "Type": "AWS::CloudFront::Distribution",
      "Properties": {
        "DistributionConfig": {
          "Enabled": "true"
        }
      }
    }
  }
}