CVE-2020-6990: Rockwellautomation Micrologix 1100 Firmware

Critical severity, CVSS 9.8. EPSS: 4.4% chance of exploitation in the next 30 days.

Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all versions, RSLogix 500 Software v12.001 and prior, The cryptographic key utilized to help protect the account password is hard coded into the RSLogix 500 binary file. An attacker could identify cryptographic keys and use it for further cryptographic attacks that could ultimately lead to a remote attacker gaining unauthorized access to the controller.

Affected products

• Rockwellautomation Micrologix 1100 Firmware: any version
• Rockwellautomation Micrologix 1400 A Firmware: any version
• Rockwellautomation Micrologix 1400 B Firmware: up to and including 21.001
• Rockwellautomation Rslogix 500: up to and including 12.001

Published 2020-03-16. Last modified 2026-06-17.