A vulnerability has been identified in SIMATIC CN 4100 (All versions < V3.0). The affected device contains an unrestricted USB port. An attacker with local access to the device could potentially misuse the port for booting another operating system and gain complete read/write access to the filesystem.
https://www.cisa.gov/news-events/ics-advisories/icsa-24-137-06
https://cert-portal.siemens.com/productcert/html/ssa-273900.html