PT-2021-20565 · 3S Smart Software Solutions · Codesys V2

Tenable Research · Published 2021-10-26 · Updated 2025-08-15 · CVE-2021-34584

Positive Technologies (AI Summary)

CVSS v3.1

9.1

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions: CODESYS V2 versions prior to V1.1.9.22

Description: The issue allows crafted web server requests to read partial stack or heap memory, potentially triggering a denial-of-service condition due to a crash in the web server.

Recommendations: For versions prior to V1.1.9.22, update to version V1.1.9.22 or later to resolve the issue.

Exploit

Fix

Buffer Over-read

Weakness Enumeration

CWE-126

Related Identifiers

CVE-2021-34584

Affected Products

Codesys V2

References · 7

• 🔥 https://tenable.com/security/research/tra-2021-47 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2021-34584 · Security Note
• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16876&token=a3f1d937f95e7034879f4f2ea8e5a99b168256a7&download= · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-34584 · Vendor Advisory
• https://t.me/cibsecurity/31198 · Telegram Post
• https://t.me/cveNotify/132530 · Telegram Post
• https://t.me/cvenotify/29451 · Telegram Post