PT-2021-20571 · 3S Smart Software Solutions · Codesys V2 Runtime Toolkit+1

Published 2021-10-26 · Updated 2025-08-15 · CVE-2021-34596

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 may cause a read access to an uninitialized pointer, resulting in a denial-of-service condition.

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

Access of Uninitialized Pointer

Weakness Enumeration

CWE-824

Related Identifiers

CVE-2021-34596

Affected Products

Codesys V2 Runtime Toolkit

Plcwinnt

References · 5

• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16878&token=e5644ec405590e66aefa62304cb8632df9fc9e9c&download= · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-34596 · Security Note
• https://osv.dev/vulnerability/CVE-2021-34596 · Vendor Advisory
• https://t.me/cibsecurity/31200 · Telegram Post
• https://t.me/cveNotify/132535 · Telegram Post