CVE-2020-6988: Rockwellautomation Micrologix 1100 Firmware

High severity, CVSS 7.5. EPSS: 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, A remote, unauthenticated attacker can send a request from the RSLogix 500 software to the victim’s MicroLogix controller. The controller will then respond to the client with used password values to authenticate the user on the client-side. This method of authentication may allow an attacker to bypass authentication altogether, disclose sensitive information, or leak credentials.

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.