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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.009 (58.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
- Amazon AWS Cloud Development Kit
- AWS Aws-Cdk — versions aws-cdk-lib >= 2.0.0, < 2.80.0, @aws-cdk/aws-eks >= 1.57.0, < 1.202.0
Weakness classification (CWE)
References
- github.com/aws/aws-cdk/security/advisories/GHSA-rx28-r23p-2qc3 (Exploit, Third Party Advisory, Mitigation)
- github.com/aws/aws-cdk/issues/25674 (Third Party Advisory, Mitigation, Issue Tracking)
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.