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CVE-2021-34596

CODESYS V2 runtime: Access of Uninitialized Pointer may result in denial-of-service

Published: Oct 26, 2021Updated: Aug 15, 2025 Sources: CVE List NVD csafCWE-824
NVD MITRE
6.5CVSSMEDIUM
EPSS Score
0.8%
Top 47.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

A crafted request may cause a read access to an uninitialized pointer in CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56, resulting in a denial-of-service condition.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-824

Affected Products

CODESYS V2CODESYSICS / OT / IoT
750-823 firmwarewagoICS / OT / IoT
750-829 firmwarewagoICS / OT / IoT
750-831 firmwarewagoICS / OT / IoT
750-832 firmwarewagoICS / OT / IoT
codesysoss-projectDEICS / OT / IoTaka codesys gmbh
wagocommercialDEICS / OT / IoT
and 26 more affected products View all →

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

1 technique
Privilege Escalation
View detailed technique mapping

References

https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16878&token=e5644ec405590e66aefa62304cb8632df9fc9e9c&download=
customers.codesys.com
https://festo.csaf-tp.certvde.com/.well-known/csaf/white/2026/fsa-202601.json
festo.csaf-tp.certvde.com
https://certvde.com/en/advisories/vendor/festo/
certvde.com
and 226 more references View all →

Timeline

Published
Oct 26, 2021
Last Updated
Aug 15, 2025

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