In SIMATIC MV400 family versions prior to v7.0.6, the ISN generator is initialized with a constant value and has constant increments. An attacker could predict and hijack TCP sessions.Referenceshttps://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdfhttps://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/
