A vulnerability has been identified in SIMATIC ET 200SP Open Controller CPU 1515SP PC (All versions), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (All versions), SIMATIC S7-1200 CPU family (All versions >= V4.0), SIMATIC S7-1500 CPU family (All versions), SIMATIC S7-1500 Software Controller (All versions), SIMATIC S7-PLCSIM Advanced (All versions). An attacker in a Man-in-the-Middle position could potentially modify network traffic exchanged on port 102/tcp, due to certain properties in the calculation used for integrity protection. In order to exploit the vulnerability, an attacker must be able to perform a Man-in-the-Middle attack. The vulnerability could impact the integrity of the communication. No public exploitation of the vulnerability was known at the time of advisory publication.