The route ran through a private APN, or access point name: a dedicated cellular data network managed by the distribution system operator. The WAGO controller reachable through the APN still had default admin credentials, while the private APN allowed client-to-client traffic. CERT's first recommendation is to audit the private APN configuration and switch on client isolation. CERT says its surveys found that Polish organizations running private APNs commonly let any device on the network reach any other. A July 30 FBI and EPA advisory on attacks against internet-facing water-sector PLCs lists a private APN among the isolated architectures operators should consider for reaching OT equipment over cellular links.