How severe is CVE-2020-6990?

CVE-2020-6990 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-6990 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-6990?

CVE-2020-6990 primarily affects Rockwellautomation Rslogix 500. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-6990?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-6990 published?

CVE-2020-6990 was published on 2020-03-16 and last updated on 2026-06-17.

CVE-2020-6990

CVE-2020-6990 is a critical-severity vulnerability in Rockwellautomation Rslogix 500 with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-798.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-798
Affected product: Rockwellautomation Rslogix 500
Published: 2020-03-16
Last modified: 2026-06-17

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, 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.

Frequently asked questions

What is CVE-2020-6990?: 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.
How severe is CVE-2020-6990?: CVE-2020-6990 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-6990 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-6990?: CVE-2020-6990 primarily affects Rockwellautomation Rslogix 500. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-6990?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-6990 published?: CVE-2020-6990 was published on 2020-03-16 and last updated on 2026-06-17.

References

https://www.us-cert.gov/ics/advisories/icsa-20-070-06

Affected products (4)

cpe:2.3:o:rockwellautomation:micrologix_1400_a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:rockwellautomation:micrologix_1400_b_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:rockwellautomation:micrologix_1100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:a:rockwellautomation:rslogix_500:*:*:*:*:*:*:*:*

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