Improper authentication in Rockwell Automation MicroLogix 1400 Controllers Series B…
Priority MEDIUM 47CWE-603Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-287.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.05418 92nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | 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 | 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 | — | No fix listed | CNA |
- 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 Vendor— Affected 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 Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:rockwellautomation:micrologix_1400_a_firmware:*:*:*:*:*:*:*:* | all versions | Vulnerable | Rockwell |
| cpe:2.3:o:rockwellautomation:micrologix_1400_b_firmware:*:*:*:*:*:*:*:* | up to 21.001 | Vulnerable | Rockwell |
| cpe:2.3:h:rockwellautomation:micrologix_1400:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Rockwell |
| cpe:2.3:o:rockwellautomation:micrologix_1100_firmware:*:*:*:*:*:*:*:* | all versions | Vulnerable | Rockwell |
| cpe:2.3:h:rockwellautomation:micrologix_1100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Rockwell |
| cpe:2.3:a:rockwellautomation:rslogix_500:*:*:*:*:*:*:*:* | up to 12.001 | Vulnerable | Rockwell |
- cpe:2.3:o:rockwellautomation:micrologix_1400_a_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Rockwell
- cpe:2.3:o:rockwellautomation:micrologix_1400_b_firmware:*:*:*:*:*:*:*:* Versions up to 21.001 Vulnerable ·Rockwell
- cpe:2.3:h:rockwellautomation:micrologix_1400:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Rockwell
- cpe:2.3:o:rockwellautomation:micrologix_1100_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Rockwell
- cpe:2.3:h:rockwellautomation:micrologix_1100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Rockwell
- cpe:2.3:a:rockwellautomation:rslogix_500:*:*:*:*:*:*:*:* Versions up to 12.001 Vulnerable ·Rockwell
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-6988
- 2026-10-03 Alias added: GHSA-8v4g-559x-qqxm
References
More Rockwell Micrologix 1100 Firmware vulnerabilities
- TI-2015-05450 Stack-based buffer overflow on Allen-Bradley MicroLogix 1100 devices before B FRN 15.000… CVSS 3.1CRITICAL 9.8
- TI-2020-05638 Hard-coded credentials in Rockwell Automation MicroLogix 1400 Controllers Series B… CVSS 3.1CRITICAL 9.8
- TI-2020-05632 Broken or risky cryptographic algorithm in Rockwell Automation MicroLogix 1400… CVSS 3.1CRITICAL 9.8
- TI-2021-12619 Improper input validation in Rockwell Automation MicroLogix 1100 CVSS 3.1HIGH 8.6
- TI-2015-05452 Allen-Bradley MicroLogix 1100 devices before B FRN 15.000 and 1400 devices before B FRN… CVSS 3.1HIGH 7.5
- TI-2022-02923 MicroLogix 1100 & 1400 Product Web Server Application Vulnerable to Denial-Of-Service Condition Attack CVSS 3.1HIGH 7.5
Sources
- CVE-2020-6988 · CVE Program
- CVE-2020-6988 · NVD
- FIRST EPSS
- GHSA-8v4g-559x-qqxm · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences