A vulnerability has been identified in SIPROTEC 5 devices with CPU variants CP200 (All versions < V7.59), SIPROTEC 5 devices with CPU variants CP300 and CP100 (All versions < V8.01), Siemens Power Meters Series 9410 (All versions < V2.2.1), Siemens Power Meters Series 9810 (All versions). An unauthenticated attacker with network access to the device could potentially insert arbitrary code which is executed before firmware verification in the device. At the time of advisory publication no public exploitation of this security vulnerability was known.