EventBridge Bus Policy Allows Wildcard Principal

What this rule checks

Detects AWS::Events::EventBusPolicy with an Allow statement targeting Principal=* (or AWS=*) without a Condition restricting access. Without the condition, any AWS account can publish events to the bus.

How to fix it

1. 1Replace wildcard Principal with specific 12-digit AWS account IDs
2. 2Or scope the policy with a Condition such as aws:PrincipalOrgID
3. 3Verify the StatementId is descriptive — easier to audit later

import { aws_events as events, aws_iam as iam } from 'aws-cdk-lib';

const bus = new events.EventBus(this, 'Bus');
bus.addToResourcePolicy(new iam.PolicyStatement({
  sid: 'AllowPutEvents',
  effect: iam.Effect.ALLOW,
  principals: [new iam.AnyPrincipal()],
  actions: ['events:PutEvents'],
  resources: [bus.eventBusArn],
}));

import { aws_events as events, aws_iam as iam } from 'aws-cdk-lib';

const bus = new events.EventBus(this, 'Bus');
bus.addToResourcePolicy(new iam.PolicyStatement({
  sid: 'AllowPutEvents',
  effect: iam.Effect.ALLOW,
  principals: [new iam.AnyPrincipal()],
  actions: ['events:PutEvents'],
  resources: [bus.eventBusArn],
  conditions: { StringEquals: { 'aws:PrincipalOrgID': 'o-abc123example' } },
}));

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 eventbridge-bus-policy-wildcard-principal and the reason is kept in the report, not silently hidden.

In .cdk-insights.json:

{
  "ignoreRules": [
    { "id": "eventbridge-bus-policy-wildcard-principal", "reason": "Why this is intentional" }
  ]
}

Or inline in your CDK code:

Validations.of(scope).acknowledge({
  id: 'cdk-insights::eventbridge-bus-policy-wildcard-principal',
  reason: 'Why this is intentional',
});

Use the rule ID eventbridge-bus-policy-wildcard-principal shown above — not the CDK-* ID from SARIF / GitHub code scanning. To dismiss every finding on one construct instead, use ignorePaths. Suppression docs →

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