Auth bypass in Amazon AWS Cloud Development Kit

CVE-2023-35165

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.

Vulnerability class: Broken Access Control

EPSS: 0.009 (55.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-35165?
CVE-2023-35165 is a medium-severity vulnerability in Amazon AWS Cloud Development Kit, classified under Incorrect Authorization. CVSS score: 6.6/10. Published 2023-06-23.
How severe is CVE-2023-35165?
Medium severity. CVSS v3 base score is 6.6 out of 10.