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CVE-2021-22659

Published: Mar 25, 2021Updated: Jun 3, 2026 Sources: CVE List NVD csafCWE-120
NVD MITRE
8.6CVSSHIGH
EPSS Score
1.7%
Top 25.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

Rockwell Automation MicroLogix 1400 Version 21.6 and below may allow a remote unauthenticated attacker to send a specially crafted Modbus packet allowing the attacker to retrieve or modify random values in the register. If successfully exploited, this may lead to a buffer overflow resulting in a denial-of-service condition. The FAULT LED will flash RED and communications may be lost. Recovery from denial-of-service condition requires the fault to be cleared by the user.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:LA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:HAvailability
High
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Weaknesses

CWE-120

Affected Products

micrologix 1400 firmwarerockwellautomationICS / OT / IoT
Rockwell Automation MicroLogix 1400n/a
rockwellautomationcommercialUSICS / OT / IoTaka rockwell automation

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight
rockwellautomation.custhelp.com
https://us-cert.cisa.gov/ics/advisories/icsa-21-033-01
us-cert.cisa.gov
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2021/icsa-21-033-01.json
raw.githubusercontent.com
and 5 more references View all →

Timeline

Published
Mar 25, 2021
Last Updated
Jun 3, 2026

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