A vulnerability has been identified in LOGO! 8 BM (incl. SIPLUS variants) (All versions < V1.81.2). An attacker with network access to the integrated web server on port 80/tcp could obtain the session ID of an active user session. A user must be logged in to the web interface. Siemens recommends to use the integrated webserver on port 80/tcp only in trusted networks.
https://cert-portal.siemens.com/productcert/pdf/ssa-087240.pdf