CVE-2020-6988

Name: CVE-2020-6988
Creator: NVD / NIST
Published: 2020-03-16T16:15:14.767+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 3.89%

Last modified Jun 17, 2026

CVE-2020-6988 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 3.89% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

3.89%

88.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Rockwellautomation	Micrologix 1400 A Firmware	All versions
Rockwellautomation	Micrologix 1400 B Firmware	<= 21.001
Rockwellautomation	Micrologix 1100 Firmware	All versions
Rockwellautomation	Rslogix 500	<= 12.001

References

https://www.us-cert.gov/ics/advisories/icsa-20-070-06Third Party Advisory, US Government Resource
https://www.us-cert.gov/ics/advisories/icsa-20-070-06Third Party Advisory, US Government Resource

Timeline

Published: Mar 16, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-6988?

How severe is CVE-2020-6988?

CVE-2020-6988 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 3.89% probability of exploitation in the next 30 days.

How do I fix CVE-2020-6988?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-6988?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST