CVE-2021-33012

State: Published
Severity: 7.5 High
Published: Jul 9, 2021
Updated: Jun 3, 2026
Reserved: May 13, 2021

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-20 IMPROPER INPUT VALIDATION CWE-20

Affected Products

Product	Versions
Rockwell Automation MicroLogix 1100n/a	All VersionsAffected

References

https://us-cert.cisa.gov/ics/advisories/icsa-21-189-01

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