CVE-2021-21866 Deserialization in CODESYS
An attacker can execute arbitrary commands by providing a specially crafted file to the CODESYS Development System due to unsafe deserialization.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-21866?
CVE-2021-21866 is a high-severity unsafe deserialization vulnerability in CODESYS, published on 2 Aug 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A unsafe deserialization vulnerability exists in the ObjectManager.plugin ProfileInformation.ProfileData functionality of CODESYS GmbH CODESYS Development System 3.5.16 and 3.5.17. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.
Weakness: CWE-502
Which versions are affected by CVE-2021-21866?
It affects 1 product.
Products include Codesys Development System.
How do I fix CVE-2021-21866?
No fix has been published for CVE-2021-21866 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2021-21866 being exploited?
There is no known exploitation of CVE-2021-21866 in the wild and no public exploit code.
Other vulnerabilities in CODESYS
- CVE-2023-3663 CODESYS: Missing integrity check in CODESYS Development System
- CVE-2021-21863 Deserialization in CODESYS
- CVE-2021-21865 Deserialization in CODESYS
- CVE-2026-44468 Incorrect Default Permissions in CODESYS Development System
- CVE-2026-44469 Incorrect Default Permissions in CODESYS Development System
Sources
Also known as GHSA-rf3q-ppf3-vv43.