CVE-2021-34593 - CVE House
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Status published High CVE-2021-34593

CODESYS V2 runtime: unauthenticated invalid requests may result in denial-of-service

Vulnerability Description

In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • This issue was discovered by Steffen Robertz and Gerhard Hechenberger from the SEC Consult Vulnerability Lab.

References

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Affected Vendor

Affected Software

CODESYS V2
Vulnerable Versions:
Runtime Toolkit 32 bit full, PLCWinNT

Timeline

Official Publish: October 26th, 2021
Last Modified: September 17th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

CWE-755

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1203 Exploitation for Client Execution
Execution
T1213 Data from Information Repositories
Collection
T1499 Endpoint Denial of Service
Impact