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TI-2021-12619 Aliases CVE-2021-33012GHSA-m5fq-q49w-wc2j

Improper input validation in Rockwell Automation MicroLogix 1100

Priority MEDIUM 48CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

Rockwell Automation MicroLogix 1100, all versions, allows a remote, unauthenticated attacker sending specially crafted commands to cause the PLC to fault when the controller is switched to RUN mode, which results in a denial-of-service condition. If successfully exploited, this vulnerability will cause the controller to fault whenever the controller is switched to RUN mode.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02637 85th 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

VendorProductAffected versionsFixed inStatusSource
—Rockwell Automation MicroLogix 1100All Versions—No fix listedCNA
  • Rockwell Automation MicroLogix 1100 Vendor— Affected All Versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:rockwellautomation:micrologix_1100_firmware:*:*:*:*:*:*:*:*all versionsVulnerableRockwell
cpe:2.3:h:rockwellautomation:micrologix_1100:-:*:*:*:*:*:*:*not specified by NVDRunning onRockwell
  • 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

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-33012
  2. 2026-10-03 Alias added: GHSA-m5fq-q49w-wc2j

References

Advisory 1

  • 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-2015-05452 Allen-Bradley MicroLogix 1100 devices before B FRN 15.000 and 1400 devices before B FRN… CVSS 3.1HIGH 7.5
  • TI-2020-05636 Improper authentication in Rockwell Automation MicroLogix 1400 Controllers Series B… 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
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences