A flaw was found in the cluster-proxy service-proxy component used in Red Hat Advanced Cluster Management for Kubernetes (RHACM) and multicluster-engine (MCE). The service-proxy appends impersonation group headers to proxied requests without first removing caller-supplied values, and the spoke ServiceAccount holds unrestricted impersonation permissions. An authenticated hub principal can inject an Impersonate-Group header to escalate to cluster-admin on every managed cluster.
Exploitability
AV:NAC:HPR:LUI:NScope
S:CImpact
C:HI:HA:H8.5/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:HOther