The vulnerability exists in the multicloud-integrations component of Red Hat Advanced Cluster Management for Kubernetes 2.11. Specifically, the Application propagation controller processes the ocm-managed-cluster annotation from Application Custom Resources without proper validation. This allows a tenant with permissions to create Applications on the hub cluster to exploit the flaw by targeting arbitrary managed clusters. Consequently, ArgoCD on the spoke clusters can be coerced into synchronizing attacker-controlled manifests, resulting in arbitrary code execution or privilege escalation on those clusters. The flaw is classified as CWE-441 (Unintended Proxy or Intermediary, 'Confused Deputy').

An attacker with low privileges (Application creation permissions) on the hub cluster can escalate privileges to cluster-admin on any connected spoke cluster. This bypasses authorization controls and allows execution of arbitrary code or commands on the managed clusters, severely compromising confidentiality, integrity, and availability across the managed Kubernetes environment.

Currently, there is no available fix or mitigation that meets Red Hat Product Security criteria for ease of use, deployment, applicability, or stability. Users should monitor Red Hat's official advisory for updates. Until a patch or official mitigation is released, restricting Application creation permissions on the hub cluster to trusted users is recommended to reduce risk.