STRATO HiDrive Desktop Client 5.0.1.0 for Windows suffers from a SYSTEM privilege escalation vulnerability through the HiDriveMaintenanceService service. This service establishes a NetNamedPipe endpoint that allows applications to connect and call publicly exposed methods. An attacker can inject and execute code by hijacking the insecure communications with the service. This vulnerability also affects Telekom MagentaCLOUD through 5.7.0.0 and 1&1 Online Storage through 6.1.0.0.