What’s Vulnerable › Vulnerabilities

CVE-2021-33541: Phoenix Contact: ILC1x Industrial controllers affected by Denial-of-Service vulnerability

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-25 · updated 2026-06-17
• Weakness: CWE-770

Description

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.

Affected products

• Phoenixcontact Ilc1X0 Firmware: all versions
• Phoenixcontact Ilc1X1 Firmware: all versions

References

• https://cert.vde.com/en-us/advisories/vde-2021-019
• https://cert.vde.com/en-us/advisories/vde-2021-019

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