What’s Vulnerable › Vulnerabilities

CVE-2021-21865

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-08-02 · updated 2026-06-17
• Weakness: CWE-502

Description

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.

Affected products

• CODESYS Development System: 3.5.16.0, 3.5.17.0

References

• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16805&token=ee583c498941d9fda86490bca98ff21928eec08a&download=
• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1301
• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16805&token=ee583c498941d9fda86490bca98ff21928eec08a&download=
• https://talosintelligence.com/vulnerability_reports/TALOS-2021-1301

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