Information disclosure in OPC UA Products Built with the .NET Framework 4.5, 4.0, and 3.5
Priority LOW 36CWE-200Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure, Denial of service
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-200 and CWE-674.
Summary
Products with Unified Automation .NET based OPC UA Client/Server SDK Bundle: Versions V3.0.7 and prior (.NET 4.5, 4.0, and 3.5 Framework versions only) are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.
Why it matters now
EPSS 0.01741 77th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
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 UA Products Built with the .NET Framework 4.5, 4.0, and 3.5 | Unified Automation .NET based OPC UA Client/Server SDK Bundle: Versions V3.0.7 and prior (.NET 4.5, 4.0, and 3.5 Framework versions only) | — | No fix listed | CNA |
- OPC UA Products Built with the .NET Framework 4.5, 4.0, and 3.5 Vendor— Affected Unified Automation .NET based OPC UA Client/Server SDK Bundle: Versions V3.0.7 and prior (.NET 4.5, 4.0, and 3.5 Framework versions only) Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:unified-automation:.net_based_opc_ua_client\/server_sdk:*:*:*:*:*:*:*:* | up to 3.0.7 | Vulnerable | Unified Automation |
| cpe:2.3:a:microsoft:.net_framework:3.5:*:*:*:*:*:*:* | 3.5 | Running on | Microsoft |
| cpe:2.3:a:microsoft:.net_framework:4.0:*:*:*:*:*:*:* | 4.0 | Running on | Microsoft |
| cpe:2.3:a:microsoft:.net_framework:4.5:*:*:*:*:*:*:* | 4.5 | Running on | Microsoft |
- cpe:2.3:a:unified-automation:.net_based_opc_ua_client\/server_sdk:*:*:*:*:*:*:*:* Versions up to 3.0.7 Vulnerable ·Unified Automation
- cpe:2.3:a:microsoft:.net_framework:3.5:*:*:*:*:*:*:* Versions 3.5 Running on ·Microsoft
- cpe:2.3:a:microsoft:.net_framework:4.0:*:*:*:*:*:*:* Versions 4.0 Running on ·Microsoft
- cpe:2.3:a:microsoft:.net_framework:4.5:*:*:*:*:*:*:* Versions 4.5 Running on ·Microsoft
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-27434
- 2026-10-03 Alias added: GHSA-43g9-fmq9-jjpm
References
Sources
- CVE-2021-27434 · CVE Program
- CVE-2021-27434 · NVD
- FIRST EPSS
- GHSA-43g9-fmq9-jjpm · GitHub Advisory Database · CC BY 4.0
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