Description

The Elastic Cloud on Kubernetes (ECK) operator reads a list of secret references from an annotation on secrets it manages, and it accepts the namespace recorded in each reference without validating that the reference is authorized for the resource being reconciled. A user whose Kubernetes permissions are limited to their own namespace can write that annotation, trigger a reconcile, and cause the operator to use its cluster-wide secret permissions to copy the contents of a secret from any other namespace into a secret the user can read.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-13T20:17:24.550Z",
  "pubdate": "2026-08-13T20:17:24.550Z",
  "executiveSummary": "This vulnerability involves an insufficient authorization flaw within the Elastic Cloud on Kubernetes (ECK) operator. Specifically, the operator fails to validate namespace boundaries when processing secret references provided via annotations on managed secrets. An authenticated malicious user whose Kubernetes permissions are strictly limited to their own namespace can exploit this weakness by crafting a malicious annotation and triggering a reconciliation event.\nUpon triggering reconciliation, the ECK operator leverages its elevated, cluster-wide secret read permissions to retrieve sensitive data from arbitrary target namespaces and subsequently replicate the contents into a secret resource accessible within the attacker's namespace. This results in an unauthorized cross-namespace information disclosure of sensitive cryptographic keys, credentials, or configuration data.\nThe affected product is the Elastic Cloud on Kubernetes (ECK) operator. The risk implication is high, as it allows privilege escalation via indirect data access, breaking the multitenancy and namespace isolation boundaries guaranteed by standard Kubernetes Role-Based Access Control (RBAC). The attacker capabilities require only standard, low-privileged access to create and modify secret resources within their own isolated namespace, combined with the ability to initiate a reconciliation process.\nSuccessful exploitation requires the attacker to have permission to write annotations to secrets managed by the operator and to prompt the reconciliation workflow. No special cluster-level administrative privileges are required by the attacker prior to exploitation, relying entirely on the over-privileged posture of the controller itself.",
  "technicalDetails": "The root cause of the vulnerability lies in improper input validation and an authorization bypass within the reconciliation logic of the Elastic Cloud on Kubernetes (ECK) operator. The vulnerable component is the secret management and reconciliation subsystem responsible for processing secret references defined within specific annotations on managed secrets.\nDuring normal operation, the ECK operator executes with cluster-wide RBAC privileges to manage resources across all namespaces. When processing a resource, the operator reads a list of secret references from an annotation attached to secrets it manages. However, the controller implementation blindly trusts the namespace recorded within each individual secret reference without verifying whether the source namespace is authorized for access by the user or entity initiating the reconciliation of the parent resource.\nThe step-by-step attack flow proceeds as follows: First, a low-privileged user with permissions restricted solely to their own namespace identifies or creates a managed secret within that namespace. Second, the user populates the designated annotation on this secret with references pointing to sensitive target secrets located in other, unauthorized namespaces (such as kube-system or production namespaces). Third, the user triggers a reconcile event, either by updating the resource or through other standard operational triggers handled by the operator. Fourth, the ECK operator processes the annotation during the reconciliation loop. Because the operator executes with cluster-wide privileges, it successfully accesses the target secret in the foreign namespace. Finally, the operator copies the contents of the unauthorized secret into the secret object residing in the attacker's namespace, rendering the sensitive data readable to the low-privileged user.\nAuthentication and privilege requirements for the attacker are minimal: the attacker must only possess local namespace-scoped Kubernetes permissions sufficient to write annotations on secrets within their designated namespace. The network exposure is internal to the Kubernetes API server communication channel used by the controller and the attacker. The payload behavior involves structural manipulation of secret annotation metadata rather than execution of arbitrary code, resulting in direct data exfiltration across logical security boundaries."
}