A vulnerability has been identified in SIMATIC ET 200SP Open Controller (incl. SIPLUS variants) (V20.8), SIMATIC S7-1500 Software Controller (V20.8). The web server of the affected products contains a vulnerability that could allow a remote attacker to trigger a denial-of-service condition by sending a specially crafted HTTP request.
https://cert-portal.siemens.com/productcert/pdf/ssa-700697.pdf