Description

Incorrect Authorization (CWE-863) in Elastic Cloud on Kubernetes (ECK) can lead to unauthorized modification of data via Metadata Spoofing (CAPEC-690). An actor holding limited Kubernetes permissions confined to a single namespace could cause attacker-controlled certificate material to be included in the Elasticsearch client trust bundle managed by ECK in a separate namespace.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.4",
  "pubDate": "2026-09-02T15:17:41.827Z",
  "pubdate": "2026-09-02T15:17:41.827Z",
  "executiveSummary": "This vulnerability, classified as CWE-863 (Incorrect Authorization), resides within Elastic Cloud on Kubernetes (ECK). The flaw permits an attacker with restricted, namespace-scoped Kubernetes privileges to perform Metadata Spoofing (CAPEC-690) against the ECK operator. By manipulating resource definitions across namespace boundaries, a malicious actor can force the injection of attacker-controlled certificate material into the Elasticsearch client trust bundle managed by ECK in a separate, potentially more privileged, namespace.\nThe primary impact involves unauthorized modification of data and potential man-in-the-middle capabilities, as the compromise of the trust bundle allows for the subversion of TLS-encrypted communication channels. The vulnerability arises from insufficient authorization checks during the cross-namespace reconciliation of resource metadata by the ECK operator. Exploitation requires the attacker to possess Kubernetes RBAC permissions sufficient to create or modify specific custom resources that the operator observes. This represents a significant security risk, as it violates the principle of namespace isolation and can lead to full compromise of data integrity within the Elasticsearch cluster by influencing trust relationships relied upon by client applications.",
  "technicalDetails": "The root cause of this vulnerability lies in an improper authorization check within the ECK operator's reconciliation logic. When the operator processes resources to build the Elasticsearch client trust bundle, it fails to adequately validate the source of the provided certificate material or the authority of the namespace initiating the request. Specifically, the operator assumes that referenced metadata or certificate secrets are implicitly trusted even when they originate from, or are manipulated within, a namespace where the user holds local administrative control, regardless of whether that user should have access to the target Elasticsearch cluster residing in a different namespace.\nThe attack flow proceeds as follows: First, an attacker identifies a target Elasticsearch cluster managed by the ECK operator in a namespace (Target-NS) to which they lack direct administrative access. Second, leveraging existing, restricted privileges within a separate namespace (Attacker-NS), the attacker creates or modifies a Kubernetes resource—such as a Secret or a ConfigMap—that contains malicious, self-signed, or otherwise unauthorized certificate material. Third, the attacker configures the target Elasticsearch resource (or an associated resource processed by the ECK operator) to reference this malicious material, effectively triggering the operator to include the attacker-controlled certificates into the global or cross-namespace client trust bundle managed by the ECK operator.\nBecause the ECK operator performs these operations with elevated privileges (typically service account permissions required for operator reconciliation), it bypasses standard Kubernetes namespace isolation. By injecting malicious certificate material into the trust bundle, the attacker can conduct Metadata Spoofing (CAPEC-690). This allows the attacker to intercept or impersonate internal services relying on these trust bundles, leading to unauthorized data modification, injection of malicious payloads into the client-server communication stream, or a complete subversion of the TLS/SSL handshake process. The impact is a total loss of trust in the inter-service communication pipeline, enabling an attacker to perform man-in-the-middle attacks that appear legitimate to the Elasticsearch cluster and its clients. Since the trust bundle is treated as authoritative, any connection verified against this bundle will accept the attacker's certificates as legitimate, providing the actor with the capability to manipulate requests, spoof identity, and potentially access sensitive data within the cluster."
}