EKS Public Endpoint Unrestricted

What this rule checks

Detects EKS clusters with the API endpoint reachable from 0.0.0.0/0 or only via the public network.

How to fix it

1. 1Enable EndpointPrivateAccess for in-VPC node communication
2. 2Restrict PublicAccessCidrs to known administrative IP ranges

import { aws_ec2 as ec2, aws_eks as eks, aws_iam as iam } from 'aws-cdk-lib';

const vpc = new ec2.Vpc(this, 'Vpc', { maxAzs: 2 });
const role = new iam.Role(this, 'EksRole', { assumedBy: new iam.ServicePrincipal('eks.amazonaws.com') });
new eks.CfnCluster(this, 'Cluster', {
  roleArn: role.roleArn,
  resourcesVpcConfig: {
    subnetIds: vpc.publicSubnets.map((s) => s.subnetId),
    endpointPublicAccess: true,
    endpointPrivateAccess: false,
    publicAccessCidrs: ['0.0.0.0/0'],
  },
});

import { aws_ec2 as ec2, aws_eks as eks, aws_iam as iam } from 'aws-cdk-lib';

const vpc = new ec2.Vpc(this, 'Vpc', { maxAzs: 2 });
const role = new iam.Role(this, 'EksRole', { assumedBy: new iam.ServicePrincipal('eks.amazonaws.com') });
new eks.CfnCluster(this, 'Cluster', {
  roleArn: role.roleArn,
  resourcesVpcConfig: {
    subnetIds: vpc.privateSubnets.map((s) => s.subnetId),
    endpointPublicAccess: true,
    endpointPrivateAccess: true,
    publicAccessCidrs: ['203.0.113.0/24'],
  },
});

CDK Insights pinpoints the exact file and line in your CDK source for every finding, so you can jump straight to the fix.

Affected resource types

Intentional? Suppress this finding

Sometimes a flag is deliberate — a genuinely public endpoint, say. You can dismiss eks-public-endpoint-unrestricted and the reason is kept in the report, not silently hidden.

In .cdk-insights.json:

{
  "ignoreRules": [
    { "id": "eks-public-endpoint-unrestricted", "reason": "Why this is intentional" }
  ]
}

Or inline in your CDK code:

Validations.of(scope).acknowledge({
  id: 'cdk-insights::eks-public-endpoint-unrestricted',
  reason: 'Why this is intentional',
});

Use the rule ID eks-public-endpoint-unrestricted shown above — not the CDK-* ID from SARIF / GitHub code scanning. To dismiss every finding on one construct instead, use ignorePaths. Suppression docs →

More EKS rules