GHSA-rx28-r23p-2qc3
MEDIUMAWS CDK EKS overly permissive trust policies
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
aws-cdk-libnpm@aws-cdk/aws-eksnpmDescription
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 (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 (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 (including v2 users). The role in question can be located in the IAM console. It will have the following name pattern:
*-ClusterCreationRole-*
MastersRole
Users with CDK version higher or equal to 1.57.0 (including v2 users) that are not specifying the mastersRole property. The role in question can be located in the IAM console. It will have the following name pattern:
*-MastersRole-*
Patches
The issue has been fixed in versions v1.202.0, v2.80.0. We recommend you upgrade to a fixed version as soon as possible. See Managing Dependencies in the CDK Developer Guide for instructions on how to do this.
The new versions no longer use the account root principal. Instead, they restrict the trust policy to the specific roles of lambda handlers that need it. This introduces some breaking changes that might require you to perform code changes. Refer to https://github.com/aws/aws-cdk/issues/25674 for a detailed discussion of options.
Workarounds
CreationRole
There is no workaround available for CreationRole.
MastersRole
To avoid creating the default MastersRole, use the mastersRole property to explicitly provide a role. For example:
new eks.Cluster(this, 'Cluster', {
...
mastersRole: iam.Role.fromRoleArn(this, 'Admin', 'arn:aws:iam::xxx:role/Admin')
});
References
https://github.com/aws/aws-cdk/issues/25674
If you have any questions or comments about this advisory we ask that you contact AWS/Amazon Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | aws-cdk-lib | ≥ 2.0.0&&< 2.80.0 | 2.80.0 |
| 📦npm | @aws-cdk/aws-eks | ≥ 1.57.0&&< 1.202.0 | 1.202.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aws-cdk-lib. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update aws-cdk-lib to 2.80.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rx28-r23p-2qc3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-rx28-r23p-2qc3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-rx28-r23p-2qc3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rx28-r23p-2qc3 in your dependencies?
O3 detects GHSA-rx28-r23p-2qc3 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.