CVE-2020-8867
Insufficient Session Expiration and TOCTOU Race Condition in OPC FOundation UA .Net Standard
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
- Record
CVE-2020-8867- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-367
- Updated
- 2026-11-02
EUVDEUVD-2021-1667
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
- Record
EUVD-2021-1667- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-9q94-v7ch-mxqw
Insufficient Session Expiration and TOCTOU Race Condition in OPC FOundation UA .Net Standard
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
- Record
GHSA-9q94-v7ch-mxqw- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-367, CWE-613
- Updated
- 2026-11-02
NVD
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
- Record
CVE-2020-8867- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-367, CWE-613
- Updated
- 2026-11-02
OSVGHSA-9q94-v7ch-mxqw
Insufficient Session Expiration and TOCTOU Race Condition in OPC FOundation UA .Net Standard
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
- Record
GHSA-9q94-v7ch-mxqw- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-367, CWE-613
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
OPCFoundation.NetStandard.Opc.UaNuGet |
through 1.4.358.30 | 1.4.359.31 |
OPCFoundation.NetStandard.Opc.UaNuGet |
before 1.4.359.31, plus listed versions 0.4.00.4.10.4.30.4.40.4.5 Show 29 moreShow less1.3.3481.3.3491.3.3501.3.350.11.3.350.31.3.350.41.3.350.51.3.350.61.3.351.71.3.352.101.3.352.111.3.352.121.3.352.91.4.353.131.4.353.141.4.353.151.4.354.16-preview1.4.354.18-preview1.4.354.19-preview1.4.354.20-preview1.4.354.211.4.354.231.4.355.24-preview1.4.355.251.4.355.261.4.356.271.4.357.281.4.358.29-preview1.4.358.30 |
1.4.359.31 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-8867 is a medium vulnerability (CVSS 5.3) in Opc Foundation Ua .net Standard, published April 22, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.64%, the 85th percentile. Fixed in OPCFoundation.NetStandard.Opc.Ua 1.4.359.31.