Rockwell Automation · Micrologix 1100 · CVE-2021-33012
**Name of the Vulnerable Software and Affected Versions**
Rockwell Automation MicroLogix 1100, all versions
**Description**
The issue allows a remote, unauthenticated attacker to send specially crafted commands to cause the PLC to fault when the controller is switched to RUN mode, resulting in a denial-of-service condition. If successfully exploited, this will cause the controller to fault whenever the controller is switched to RUN mode.
**Recommendations**
For Rockwell Automation MicroLogix 1100, all versions, consider temporarily restricting access to the controller when switching to RUN mode until a patch is available. As a mitigation measure, restrict the ability to send specially crafted commands to the PLC to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.