Time-of-check time-of-use race condition in OPC Foundation UA .NET Standard
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-613.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| OPC Foundation | UA .NET Standard | 1.04.358.30 | — | No fix listed | CNA |
| — | OPCFoundation.NetStandard.Opc.Ua (NuGet) | before 1.4.359.31 | 1.4.359.31 | Patch available | GHSA-9q94-v7ch-mxqw |
- UA .NET Standard VendorOPC Foundation Affected 1.04.358.30 Fixed in — No fix listed CNA
- OPCFoundation.NetStandard.Opc.Ua (NuGet) Vendor— Affected before 1.4.359.31 Fixed in 1.4.359.31 Patch available GHSA-9q94-v7ch-mxqw
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:opcfoundation:unified_architecture_.net-standard:*:*:*:*:*:*:*:* | up to 1.04.358.30 | Vulnerable | OPC Foundation |
- cpe:2.3:a:opcfoundation:unified_architecture_.net-standard:*:*:*:*:*:*:*:* Versions up to 1.04.358.30 Vulnerable ·OPC Foundation
Remediation
- Fix · GHSA-9q94-v7ch-mxqw OPCFoundation.NetStandard.Opc.Ua (NuGet) Fixed in 1.4.359.31 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2020-8867
- 2026-10-03 Alias added: GHSA-9q94-v7ch-mxqw
References
Advisory 3
More OPC Foundation Unified Architecture .net-standard vulnerabilities
- TI-2018-08666 Buffer overflow in OPC UA applications allows remote attackers to trigger a stack… CVSS 3.0HIGH 7.5
Sources
- CVE-2020-8867 · CVE Program
- CVE-2020-8867 · NVD
- FIRST EPSS
- GHSA-9q94-v7ch-mxqw · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences