Home/CVE/A unsafe deserialization vulnerability exists in the PackageManagement.plugin ExtensionMethods.Clone() functionality of
CVE

CVE-2021-21865

A unsafe deserialization vulnerability exists in the PackageManagement.plugin ExtensionMethods.Clone() functionality of

A unsafe deserialization vulnerability exists in the PackageManagement.plugin ExtensionMethods.Clone() functionality of CODESYS GmbH CODESYS Development System 3.5.16. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.

HIGH · CVSS 7.8 EPSS 0.00062
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-502Deserialization of Untrusted Data
CWE-502Deserialization of Untrusted Data
▤

Affected Products & Versions

1
codesys development systemall versions
▣

Scoring & Timeline

7.8
HIGH · CVSS v3.1 · talos-cna@cisco.com
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 NVD02 Aug 2021 · 09:15 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
⚑

Vendor Advisories

1
cisa-csafcisa-csaf-csaf_files-OT-white-2026-icsa-26-076-01
🔗

References & Sources

2
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=16805&token=ee583c498941d9fda86490bca98ff21928eec08a&download=MitigationPatchVendor Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1301Not ApplicableThird Party Advisory
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