CVE-2020-29457 is a medium-severity (CVSS 4.4) CWE-295 vulnerability in OPCFoundation.NetStandard.Opc.Ua.Core. A fix is available for OPCFoundation.NetStandard.Opc.Ua.Core — see the affected versions and patch details below.
Improper Certificate Validation in OPCFoundation.NetStandard.Opc.Ua.Core
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-29457 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
OPCFoundation.NetStandard.Opc.Ua.CoreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
A Privilege Elevation vulnerability in OPC UA .NET Standard Stack 1.4.363.107 could allow a rogue application to establish a secure connection.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | OPCFoundation.NetStandard.Opc.Ua.Core | all versions | 1.4.365.10dotnet add package OPCFoundation.NetStandard.Opc.Ua.Core --version 1.4.365.10 |
Affected Products
ua-.netstandardopcfoundationDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for OPCFoundation.NetStandard.Opc.Ua.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update OPCFoundation.NetStandard.Opc.Ua.Core to 1.4.365.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-29457 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2020-29457 in your dependencies?
Find it across NuGet, including transitive dependencies.