A vulnerability has been identified in SCALANCE X204RNA (HSR) (All versions < V3.2.7), SCALANCE X204RNA (PRP) (All versions < V3.2.7), SCALANCE X204RNA EEC (HSR) (All versions < V3.2.7), SCALANCE X204RNA EEC (PRP) (All versions < V3.2.7), SCALANCE X204RNA EEC (PRP/HSR) (All versions < V3.2.7). The webserver of affected devices calculates session ids and nonces in an insecure manner. This could allow an unauthenticated remote attacker to brute-force session ids and hijack existing sessions.
https://cert-portal.siemens.com/productcert/pdf/ssa-363821.pdf