Home/CVE/CODESYS Control Runtime system before 3.5.17.10 has a Heap-based Buffer Overflow.
CVE

CVE-2021-33485

CODESYS Control Runtime system before 3.5.17.10 has a Heap-based Buffer Overflow.

CODESYS Control Runtime system before 3.5.17.10 has a Heap-based Buffer Overflow.

CRITICAL · CVSS 9.8 EPSS 0.00394
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules4 YARA rules0
⬡

Weakness Classification

CWE-787Out-of-bounds Write
▤

Affected Products & Versions

8
codesys control< 4.2.0.0
codesys control<= 4.2.0.0
codesys control rte< 3.5.17.10
codesys control runtime system toolkit< 3.5.17.10
codesys control win sl< 3.5.17.10
codesys embedded target visu toolkit< 3.5.17.10
codesys hmi< 3.5.17.10
codesys remote target visu toolkit< 3.5.17.10
◈

Sigma Hunt Rules

4
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious Control Panel DLL Load
producthighControl Panel Items
producthighSystem Control Panel Item Loaded From Uncommon Location
producthighEnabled User Right in AD to Control User Objects
▣

Scoring & Timeline

9.8
CRITICAL · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD03 Aug 2021 · 04:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
⚑

Vendor Advisories

2
cisa-csafcisa-csaf-csaf_files-OT-white-2025-icsa-25-273-04
cisa-csafcisa-csaf-csaf_files-OT-white-2026-icsa-26-076-01
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=14805&token=f0b86f99bb302ddd4aadec483aed5f5d3fddbf1a&download=Vendor Advisory
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