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CVE-2021-33012

Published: Jul 9, 2021Updated: Jun 3, 2026 Sources: CVE List NVD csafCWE-20
NVD MITRE
8.6CVSSHIGH
EPSS Score
1.9%
Top 22.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:CC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-20NVD-CWE-noinfo

Affected Products

micrologix 1100 firmwarerockwellautomationICS / OT / IoT
Rockwell Automation MicroLogix 1100n/a
rockwellautomationcommercialUSICS / OT / IoTaka rockwell automation

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://us-cert.cisa.gov/ics/advisories/icsa-21-189-01
us-cert.cisa.gov
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2021/icsa-21-189-01.json
raw.githubusercontent.com
https://www.cisa.gov/news-events/ics-advisories/icsa-21-189-01
cisa.gov
and 4 more references View all →

Timeline

Published
Jul 9, 2021
Last Updated
Jun 3, 2026

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