TI-2021-12936 Aliases CVE-2021-33541 GHSA-jwj9-vx74-vv26

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

LOW 36CWE-770Published 2021-06-25 · Updated 2024-09-16

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

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.

Why it matters now

EPSS 0.01493 74th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Phoenix Contact	ILC1x	ILC1x0 all variants; ILC1x1 all variants	—	No fix listed	CNA

ILC1x VendorPhoenix Contact Affected ILC1x0 all variants; ILC1x1 all variants Fixed in — No fix listed CNA

CPE configurations NVD · 4

CPE	Versions	Role	Vendor
cpe:2.3:o:phoenixcontact:ilc1x0_firmware::::::::	all versions	Vulnerable	Phoenixcontact
cpe:2.3:h:phoenixcontact:ilc1x0:-:::::::*	not specified by NVD	Running on	Phoenixcontact
cpe:2.3:o:phoenixcontact:ilc1x1_firmware::::::::	all versions	Vulnerable	Phoenixcontact
cpe:2.3:h:phoenixcontact:ilc1x1:-:::::::*	not specified by NVD	Running on	Phoenixcontact

cpe:2.3:o:phoenixcontact:ilc1x0_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Phoenixcontact
cpe:2.3:h:phoenixcontact:ilc1x0:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
cpe:2.3:o:phoenixcontact:ilc1x1_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Phoenixcontact
cpe:2.3:h:phoenixcontact:ilc1x1:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2021-33541
2026-10-03 Alias added: GHSA-jwj9-vx74-vv26

References

Advisory 1

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

TI-2014-07463 Phoenix Contact Software ProConOs and MultiProg Missing Authentication for Critical Function CVSS 2.0CRITICAL 10.0
TI-2024-17093 PHOENIX CONTACT: Remote code execution in CHARX Series CVSS 3.1CRITICAL 9.8
TI-2022-13692 Insufficient Verification of Data Vulnerability in PHOENIX CONTACT classic line industrial controllers CVSS 3.1CRITICAL 9.8
TI-2026-21959 Remote code execution via uploading a malicious IODD file CVSS 3.1CRITICAL 9.8
TI-2026-21940 Authentication Bypass in _account_log CVSS 3.1CRITICAL 9.8
TI-2023-03334 PHOENIX CONTACT: OS Command Injection in WP 6xxx Web panels CVSS 3.1CRITICAL 10.0

See all 194 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences