CVE-2021-21867
A unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream...
An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray 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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray 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.
- Record
CVE-2021-21867- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2021-9038
An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray 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.
- Record
EUVD-2021-9038- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-847p-f9h7-f5x2
A unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream...
A unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray 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.
- Record
GHSA-847p-f9h7-f5x2- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
NVD
An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray 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.
- Record
CVE-2021-21867- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-502
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21867 is a high vulnerability (CVSS 8.8) in 3s-smart Software Solutions Codesys, published August 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.77%, the 78th percentile. No source names a fixed version.