Provider-credential-controller: provider-credential-controller: cross-namespace credential propagation via attacker-controlled copiedfrom labels bypasses authorization

A flaw was found in the provider-credential-controller component of multicluster-engine (MCE). An attacker with specific permissions on the hub cluster, and knowledge of a prior credential value, could exploit an authorization bypass vulnerability. By manipulating `copiedFrom` labels, the attacker could intercept newly rotated provider credentials, leading to unauthorized information disclosure. This allows access to sensitive credentials that should otherwise be protected.

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.