CVE-2020-6988: Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all versions, RSLogix 500 Softwa

Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all versions, RSLogix 500 Softwa

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.

Description from the National Vulnerability Database, published by ics-cert@hq.dhs.gov

What it means for a small business

If your business uses Micrologix 1400 A Firmware, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 4.0%, top 9% of all CVEs. That’s above average: worth scheduling this week. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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