CVE-2020-6998

Name: CVE-2020-6998
Creator: NVD / NIST
Published: 2022-07-27T21:15:08.297+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.6/10EPSS 1.74%

Last modified Jun 17, 2026

CVE-2020-6998 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. The connection establishment algorithm found in Rockwell Automation CompactLogix 5370 and ControlLogix 5570 versions 33 and prior does not sufficiently manage its control flow during execution, creating an infinite loop. This may allow an attacker to send specially crafted CIP packet requests to a controller, which may cause denial-of-service conditions in communications with other products.. EPSS estimates a 1.74% chance of exploitation in the next 30 days.

Description

The connection establishment algorithm found in Rockwell Automation CompactLogix 5370 and ControlLogix 5570 versions 33 and prior does not sufficiently manage its control flow during execution, creating an infinite loop. This may allow an attacker to send specially crafted CIP packet requests to a controller, which may cause denial-of-service conditions in communications with other products.

Metrics

CVSS 3.1

8.6/10

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

EPSS Probability

1.74%

74.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Rockwellautomation	Armor Compact Guardlogix 5370 Firmware	<= 33
Rockwellautomation	Compact Guardlogix 5370 Firmware	<= 33
Rockwellautomation	Compactlogix 5370 L1 Firmware	<= 33
Rockwellautomation	Compactlogix 5370 L2 Firmware	<= 33
Rockwellautomation	Compactlogix 5370 L3 Firmware	<= 33
Rockwellautomation	Controllogix 5570 Firmware	<= 33
Rockwellautomation	Guardlogix 5560 Firmware	<= 33
Rockwellautomation	Guardlogix 5570 Firmware	<= 33
Rockwellautomation	Guardlogix 5580 Firmware	<= 33

References

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1130398Permissions Required, Vendor Advisory
https://www.cisa.gov/uscert/ics/advisories/icsa-21-061-02Third Party Advisory, US Government Resource
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1130398Permissions Required, Vendor Advisory
https://www.cisa.gov/uscert/ics/advisories/icsa-21-061-02Third Party Advisory, US Government Resource

Timeline

Published: Jul 27, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-6998?

How severe is CVE-2020-6998?

CVE-2020-6998 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 1.74% probability of exploitation in the next 30 days.

How do I fix CVE-2020-6998?

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-2020-6998?

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

Scan your code now

Source: NVD / NIST