CVE-2021-33012: Rockwellautomation Micrologix 1100 Firmware

High severity, CVSS 8.6. EPSS: 2.6% chance of exploitation in the next 30 days.

Rockwell Automation MicroLogix 1100, all versions, allows a remote, unauthenticated attacker sending specially crafted commands to cause the PLC to fault when the controller is switched to RUN mode, which results in a denial-of-service condition. If successfully exploited, this vulnerability will cause the controller to fault whenever the controller is switched to RUN mode.

Affected products

• Rockwellautomation Micrologix 1100 Firmware: any version

Published 2021-07-09. Last modified 2026-06-17.