PT-2021-20570 · 3S Smart Software Solutions · Codesys V2 Runtime Toolkit+1

Published 2021-10-26 · Updated 2025-08-15 · CVE-2021-34595

Positive Technologies (AI Summary)

CVSS v3.1

8.1

High

Base vector

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

Name of the Vulnerable Software and Affected Versions: CODESYS V2 Runtime Toolkit 32 Bit full versions prior to V2.4.7.56 PLCWinNT versions prior to V2.4.7.56

Description: A crafted request with invalid offsets may cause an out-of-bounds read or write access, resulting in a denial-of-service condition or local memory overwrite.

Recommendations: For CODESYS V2 Runtime Toolkit 32 Bit full versions prior to V2.4.7.56, update to version V2.4.7.56 or later. For PLCWinNT versions prior to V2.4.7.56, update to version V2.4.7.56 or later.

Fix

DoS

Buffer Overflow

Weakness Enumeration

CWE-823

CWE-119

Related Identifiers

CVE-2021-34595

Affected Products

Codesys V2 Runtime Toolkit

Plcwinnt

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2021-34595 · Security Note
• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16878&token=e5644ec405590e66aefa62304cb8632df9fc9e9c&download= · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-34595 · Vendor Advisory
• https://t.me/cveNotify/132534 · Telegram Post
• https://t.me/cibsecurity/31197 · Telegram Post