CVE-2023-35165
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
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 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 CVE-2023-35165 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 CVE-2023-35165 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 CVE-2023-35165. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-35165 in your dependencies?
O3 detects CVE-2023-35165 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.