How severe is CVE-2020-6988?

CVE-2020-6988 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-6988 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-2020-6988?

CVE-2020-6988 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-2020-6988?

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

When was CVE-2020-6988 published?

CVE-2020-6988 was published on 2020-03-16 and last updated on 2026-06-17.

CVE-2020-6988

CVE-2020-6988 is a high-severity vulnerability in Rockwellautomation Rslogix 500 with a CVSS 3.x base score of 7.5. 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-287.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
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, 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.

Frequently asked questions

What is 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 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.
How severe is CVE-2020-6988?: CVE-2020-6988 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-6988 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-2020-6988?: CVE-2020-6988 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-2020-6988?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-6988 published?: CVE-2020-6988 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:*:*:*:*:*:*:*:*

More vulnerabilities in Rockwellautomation Rslogix 500

CVE-2020-6990 — Critical (CVSS 9.8): Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100…
CVE-2024-7847 — High (CVSS 7.7): VULNERABILITY DETAILS Rockwell Automation used the latest versions of the CVSS scoring system to assess the following…
CVE-2020-6984 — High (CVSS 7.5): Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100…
CVE-2020-6980 — Low (CVSS 3.3): Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100…

All CVEs affecting Rockwellautomation Rslogix 500 →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-20317 — Critical (CVSS 10.0): As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Workload engineering…
CVE-2026-19977 — Critical (CVSS 10.0): A vulnerability was detected in EFM ipTIME A3004T 14.19.0. The affected element is the function…
CVE-2026-59500 — Critical (CVSS 10.0): CWE-287: Improper Authentication
CVE-2024-27253 — Critical (CVSS 10.0): IBM DOORS Next 7.0.3 through 7.0.3 Interim Fix 018 could allow an authenticated user to bypass security logic to…
CVE-2026-56162 — Critical (CVSS 10.0): Improper authentication in Azure SQL Database allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-62825 — Critical (CVSS 10.0): Improper authentication in Azure Key Vault allows an unauthorized attacker to elevate privileges over a network.

Browse all CWE-287 (Improper Authentication) vulnerabilities →