Cross-service confused deputy prevention

The confused deputy problem is a security issue where an entity that doesn't have permission to perform an action can coerce a more-privileged entity to perform the action. In Amazon, cross-service impersonation can result in the confused deputy problem. Cross-service impersonation can occur when one service (the calling service) calls another service (the called service). The calling service can be manipulated to use its permissions to act on another customer's resources in a way it should not otherwise have permission to access. To prevent this, Amazon provides tools that help you protect your data for all services with service principals that have been given access to resources in your account. For more information, see Cross-service confused deputy prevention in the IAM User Guide.

We recommend using the aws:SourceArn and aws:SourceAccount global condition context keys in resource-based policies to limit the permissions that Amazon Redshift gives another service to the resource. If the aws:SourceArn value doesn't contain the account ID, such as an Amazon S3 bucket ARN, you must use both global condition context keys to limit permissions. If you use both global condition context keys and the aws:SourceArn value contains the account ID, the aws:SourceAccount value and the account in the aws:SourceArn value must use the same account ID when used in the same policy statement.

The following example shows a policy that you can apply to limit the confused deputy problem for Amazon Redshift.

{
  "Version": "2012-10-17",
  "Statement": {
    "Sid": "ConfusedDeputyPreventionForRedshift",
    "Effect": "Allow",
    "Principal": {
      "Service": "redshift.amazonaws.com"
    },
    "Action": "sts:AssumeRole",
    "Condition": {
      "ArnLike": {
        "aws:SourceArn": "arn:aws:redshift:us-east-1:123456789012:cluster:my-cluster"
      },
      "StringEquals": {
        "aws:SourceAccount": "123456789012"
      }
    }
  }
}

The following example shows a policy for Amazon Redshift Serverless.

{
  "Version": "2012-10-17",
  "Statement": {
    "Sid": "ConfusedDeputyPreventionForRedshiftServerless",
    "Effect": "Allow",
    "Principal": {
      "Service": "redshift-serverless.amazonaws.com"
    },
    "Action": "sts:AssumeRole",
    "Condition": {
      "ArnLike": {
        "aws:SourceArn": "arn:aws:redshift-serverless:us-east-1:123456789012:workgroup/my-workgroup"
      },
      "StringEquals": {
        "aws:SourceAccount": "123456789012"
      }
    }
  }
}