AWS Cloud Development Kit (AWS CDK) is an open-source software development framework to define cloud infrastructure in code and provision it through AWS CloudFormation. In the packages `aws-cdk-lib` 2.0.0 until 2.80.0 and `@aws-cdk/aws-eks` 1.57.0 until 1.202.0, `eks.Cluster` and `eks.FargateCluster` constructs create two roles, `CreationRole` and `default MastersRole`, that have an overly permissive trust policy. The first, referred to as the `CreationRole`, is used by lambda handlers to create the cluster and deploy Kubernetes resources (e.g `KubernetesManifest`, `HelmChart`, ...) onto it. Users with CDK version higher or equal to 1.62.0 (including v2 users) may be affected. The second, referred to as the `default MastersRole`, is provisioned only if the `mastersRole` property isn't provided and has permissions to execute `kubectl` commands on the cluster. Users with CDK version higher or equal to 1.57.0 (including v2 users) may be affected.
The issue has been fixed in `@aws-cdk/aws-eks` v1.202.0 and `aws-cdk-lib` v2.80.0. These versions no longer use the account root principal. Instead, they restrict the trust policy to the specific roles of lambda handlers that need it. There is no workaround available for CreationRole. To avoid creating the `default MastersRole`, use the `mastersRole` property to explicitly provide a role.
Affected: npm: aws-cdk-lib, npm: @aws-cdk/aws-eks
If you are using the `eks.Cluster` or `eks.FargateCluster` construct we need you to take action. Other users are not affected and can stop reading.
### Impact
The AWS Cloud Development Kit (CDK) allows for the definition of Amazon Elastic Container Service for Kubernetes (EKS) clusters. `eks.Cluster` and `eks.FargateCluster` constructs create two roles that have an overly permissive trust policy. The first, referred to as the _CreationRole_, is used by lambda handlers to create the cluster and deploy Kubernetes resources (e.g `KubernetesManifest`, `HelmChart`, ...) onto it. Users with CDK version higher or equal to [1.62.0](https://github.com/aws/aws-cdk/releases/tag/v1.62.0) (including v2 users) will be affected. The second, referred to as the _default MastersRole_, is provisioned only if the `mastersRole` property isn't provided and has permissions to execute `kubectl` commands on the cluster. Users with CDK version higher or equal to [1.57.0](https://github.com/aws/aws-cdk/releases/tag/v1.57.0) (including v2 users) will be affected. Both these roles use the account root principal in their trust policy, which allows any identity in the account with the appropriate `sts:AssumeRole `permissions to assume it. For example, this can happen if another role in your account has `sts:AssumeRole` permissions on `Resource: "*"`.
#### CreationRole
Users with CDK version higher or equal to [1.62.0](https://github.com/aws/aws-cdk/releases/tag/v1.62.0) (including v2 users).…