PT-2021-20567 · 3S Smart Software Solutions · Codesys

Tenable Research · Published 2021-10-26 · Updated 2025-08-15 · CVE-2021-34586

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

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

Description: The issue is related to crafted web server requests that may cause a Null pointer dereference in the CODESYS web server, potentially resulting in a denial-of-service condition.

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

Exploit

Fix

DoS

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2021-34586

Affected Products

Codesys

References · 6

• 🔥 https://tenable.com/security/research/tra-2021-47 · Exploit
• https://osv.dev/vulnerability/CVE-2021-34586 · Vendor Advisory
• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16876&token=a3f1d937f95e7034879f4f2ea8e5a99b168256a7&download= · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-34586 · Security Note
• https://t.me/cibsecurity/31204 · Telegram Post
• https://t.me/cveNotify/132532 · Telegram Post