AWS045.md

Pattern: CloudFront distribution does not have a WAF in front

Issue: -

Description

You should configure a Web Application Firewall in front of your CloudFront distribution. This will mitigate many types of attacks on your web application.

Resolution: Enable WAF for the CloudFront distribution.

Examples

Example of incorrect code:

resource "aws_cloudfront_distribution" "bad_example" {
  origin_group {
    origin_id = "groupS3"

    failover_criteria {
      status_codes = [403, 404, 500, 502]
    }

    member {
      origin_id = "primaryS3"
    }
  }

  origin {
    domain_name = aws_s3_bucket.primary.bucket_regional_domain_name
    origin_id   = "primaryS3"

    s3_origin_config {
      origin_access_identity = aws_cloudfront_origin_access_identity.default.cloudfront_access_identity_path
    }
  }

  origin {
    domain_name = aws_s3_bucket.failover.bucket_regional_domain_name
    origin_id   = "failoverS3"

    s3_origin_config {
      origin_access_identity = aws_cloudfront_origin_access_identity.default.cloudfront_access_identity_path
    }
  }

  default_cache_behavior {
    target_origin_id = "groupS3"
  }
}

Example of correct code:

resource "aws_cloudfront_distribution" "good_example" {

  origin {
    domain_name = aws_s3_bucket.primary.bucket_regional_domain_name
    origin_id   = "primaryS3"

    s3_origin_config {
      origin_access_identity = aws_cloudfront_origin_access_identity.default.cloudfront_access_identity_path
    }
  }

  origin {
    domain_name = aws_s3_bucket.failover.bucket_regional_domain_name
    origin_id   = "failoverS3"

    s3_origin_config {
      origin_access_identity = aws_cloudfront_origin_access_identity.default.cloudfront_access_identity_path
    }
  }

  default_cache_behavior {
    target_origin_id = "groupS3"
  }

  web_acl_id = "waf_id"
}