Uncontrolled recursion in OPC Foundation OPC UA .NET Standard and OPC UA .NET Legacy
Priority LOW 37CWE-674Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-674.
Summary
OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.
Why it matters now
EPSS 0.0195 80th 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 Foundation OPC UA .NET Standard and OPC UA .NET Legacy | OPC UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy | — | No fix listed | CNA |
- OPC Foundation OPC UA .NET Standard and OPC UA .NET Legacy Vendor— Affected OPC UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:opcfoundation:ua-.net-legacy:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | OPC Foundation |
| cpe:2.3:a:opcfoundation:ua_.net_standard_stack:*:*:*:*:*:*:*:* | before 1.4.365.48 | Vulnerable | OPC Foundation |
- cpe:2.3:a:opcfoundation:ua-.net-legacy:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·OPC Foundation
- cpe:2.3:a:opcfoundation:ua_.net_standard_stack:*:*:*:*:*:*:*:* Versions before 1.4.365.48 Vulnerable ·OPC Foundation
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-27432
- 2026-10-03 Alias added: GHSA-5rm8-9376-7gg5
References
More OPC Foundation Ua-.net-legacy vulnerabilities
- TI-2017-08865 Unsigned versions of the DLLs distributed by the OPC Foundation may be replaced with malicious code. CVSS 3.0HIGH 8.8
- TI-2018-09034 An XXE vulnerability in the OPC UA Java and .NET Legacy Stack can allow remote attackers to trigger a denial of service. CVSS 3.0HIGH 8.2
- TI-2018-05465 An issue was discovered in OPC UA .NET Standard Stack and Sample Code before GitHub… CVSS 3.0MEDIUM 5.3
- TI-2018-08667 Failure to validate certificates in OPC Foundation UA Client Applications communicating… CVSS 3.0MEDIUM 5.3
Sources
- CVE-2021-27432 · CVE Program
- CVE-2021-27432 · NVD
- FIRST EPSS
- GHSA-5rm8-9376-7gg5 · 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