A vulnerability has been identified in SIMATIC CN 4100 (All versions < V3.0). The affected device contains undocumented users and credentials. An attacker could misuse the credentials to compromise the device locally or over the network.
https://www.cisa.gov/news-events/ics-advisories/icsa-24-137-06
https://cert-portal.siemens.com/productcert/html/ssa-273900.html