Describe CVE-2021-37204.
What is CVE-2021-37204?
A vulnerability has been identified in SIMATIC Drive Controller family (All versions < V2.9.2), SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants) (All versions), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions < V21.9), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions >= V21.9 < V21.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 Ready4Linux (All versions), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions < V4.5.0), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions >= V4.5.0 < V4.5.2), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions < V2.9.2), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions >= V2.9.2 < V2.9.4), SIMATIC S7-1500 Software Controller (All versions < V21.9), SIMATIC S7-1500 Software Controller (All versions >= V21.9 < V21.9.4), SIMATIC S7-PLCSIM Advanced (All versions < V4.0), SIMATIC S7-PLCSIM Advanced (All versions >= V4.0 < V4.0 SP1), SIPLUS TIM 1531 IRC (All versions < V2.3.6), TIM 1531 IRC (All versions < V2.3.6). An unauthenticated attacker could cause a denial-of-service condition in a PLC when sending specially prepared packet over port 102/tcp. A restart of the affected device is needed to restore normal operations..