Phoenix Contact Classic Line Controllers ILC1x0 and ILC1x1 in all versions/variants are affected by a Denial-of-Service vulnerability. The communication protocols and device access do not feature authentication measures. Remote attackers can use specially crafted IP packets to cause a denial of service on the PLC's network communication module. A successful attack stops all network communication. To restore the network connectivity the device needs to be restarted. The automation task is not affected.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-33541
• https://cert.vde.com/en-us/advisories/vde-2021-019