CVE-2021-33012

HIGH
8.6
CVSS Score
Published: July 9, 2021 at 02:03 PM UTC
Updated: June 17, 2026 at 03:54 AM UTC
2 products affected across 1 vendorMicrologix 1100 FirmwareMicroLogix 1100

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Severity
HIGH8.6
Exploit prediction
EPSS 3%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
rockwellautomation-micrologix-1100 (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_MISCThird Party AdvisoryUS Government Resource
https://us-cert.cisa.gov/ics/advisories/icsa-21-189-01

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20NVD-CWE-noinfo

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