# CVE-2018-8356: Improper Certificate Validation in Microsoft .NET Framework components > Attackers can bypass certificate validation in Microsoft .NET Framework components, potentially undermining secure communications. - **Severity:** Medium 5.5 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 Jul 2018 - **Updated:** 5 Aug 2024 - **Also known as:** GHSA-p9wx-v264-q34p ## What is CVE-2018-8356? CVE-2018-8356 is a medium-severity vulnerability in Microsoft .Net Framework, published on 11 Jul 2018. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description A security feature bypass vulnerability exists when Microsoft .NET Framework components do not correctly validate certificates, aka ".NET Framework Security Feature Bypass Vulnerability." This affects .NET Framework 4.7.2, Microsoft .NET Framework 3.0, Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2, ASP.NET Core 1.1, Microsoft .NET Framework 4.5.2, ASP.NET Core 2.0, ASP.NET Core 1.0, .NET Core 1.1, Microsoft .NET Framework 3.5, Microsoft .NET Framework 3.5.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2, .NET Core 1.0, .NET Core 2.0, Microsoft .NET Framework 4.6, Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.1/4.7.2, Microsoft .NET Framework 4.7.2. Weakness: CWE-295 (Improper Certificate Validation) ## Which versions are affected by CVE-2018-8356? 40 open source packages ship an affected version, including System.ServiceModel.NetTcp, System.Private.ServiceModel and System.ServiceModel.Duplex. It affects 5 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `System.ServiceModel.NetTcp` | NuGet | From 4.0.0 | 4.1.3 | | `System.ServiceModel.NetTcp` | NuGet | From 4.0.0 | 4.1.3 | | `System.ServiceModel.NetTcp` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.NetTcp` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.NetTcp` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.NetTcp` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.NetTcp` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.NetTcp` | NuGet | From 4.5.0 | 4.5.3 | | `System.Private.ServiceModel` | NuGet | From 4.0.0 | 4.1.3 | | `System.Private.ServiceModel` | NuGet | From 4.0.0 | 4.1.3 | | `System.Private.ServiceModel` | NuGet | From 4.3.0 | 4.3.3 | | `System.Private.ServiceModel` | NuGet | From 4.3.0 | 4.3.3 | | `System.Private.ServiceModel` | NuGet | From 4.4.0 | 4.4.4 | | `System.Private.ServiceModel` | NuGet | From 4.4.0 | 4.4.4 | | `System.Private.ServiceModel` | NuGet | From 4.5.0 | 4.5.3 | | `System.Private.ServiceModel` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.Duplex` | NuGet | From 4.0.0 | 4.0.4 | | `System.ServiceModel.Duplex` | NuGet | From 4.0.0 | 4.0.4 | | `System.ServiceModel.Duplex` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.Duplex` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.Duplex` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.Duplex` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.Duplex` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.Duplex` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.Http` | NuGet | From 4.0.0 | 4.1.3 | | `System.ServiceModel.Http` | NuGet | From 4.0.0 | 4.1.3 | | `System.ServiceModel.Http` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.Http` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.Http` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.Http` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.Http` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.Http` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.Primitives` | NuGet | From 4.0.0 | 4.1.3 | | `System.ServiceModel.Primitives` | NuGet | From 4.0.0 | 4.1.3 | | `System.ServiceModel.Primitives` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.Primitives` | NuGet | From 4.3.0 | 4.3.3 | | `System.ServiceModel.Primitives` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.Primitives` | NuGet | From 4.4.0 | 4.4.4 | | `System.ServiceModel.Primitives` | NuGet | From 4.5.0 | 4.5.3 | | `System.ServiceModel.Primitives` | NuGet | From 4.5.0 | 4.5.3 | Products: Microsoft .Net Core, Microsoft .Net Framework, Microsoft .Net Framework Developer Pack, Microsoft Asp.net Core, Microsoft Powershell Core. ## How do I fix CVE-2018-8356? Upgrade System.ServiceModel.NetTcp to a fixed version for your release line: 4.1.3, 4.3.3, 4.4.4 or 4.5.3. ## Is CVE-2018-8356 being exploited? There is no known exploitation of CVE-2018-8356 in the wild and no public exploit code. ## Other vulnerabilities in Microsoft .Net Framework - [CVE-2020-1147](https://insights.sbomify.com/CVE-2020-1147/): Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution (high 7.8, exploited in the wild) - [CVE-2020-0605](https://insights.sbomify.com/CVE-2020-0605/): Code injection in .NET Core (high 8.8) - [CVE-2020-0606](https://insights.sbomify.com/CVE-2020-0606/): Remote code execution in Microsoft.WindowsDesktop.App.Ref (high 8.8) - [CVE-2019-1301](https://insights.sbomify.com/CVE-2019-1301/): High severity vulnerability that affects System.Management.Automation (high 7.5) - [CVE-2019-0820](https://insights.sbomify.com/CVE-2019-0820/): Regular Expression Denial of Service in System.Text.RegularExpressions (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2018-8356 and fix it if it is affected. What it is: CVE-2018-8356 is a medium-severity vulnerability in Microsoft .Net Framework, published on 11 Jul 2018. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2018-8356 in the wild and no public exploit code. Affected packages and fixed versions: - System.ServiceModel.NetTcp (NuGet): affected from 4.0.0; fixed in 4.1.3 - System.ServiceModel.NetTcp (NuGet): affected from 4.0.0; fixed in 4.1.3 - System.ServiceModel.NetTcp (NuGet): affected from 4.3.0; fixed in 4.3.3 - System.ServiceModel.NetTcp (NuGet): affected from 4.3.0; fixed in 4.3.3 - System.ServiceModel.NetTcp (NuGet): affected from 4.4.0; fixed in 4.4.4 - System.ServiceModel.NetTcp (NuGet): affected from 4.4.0; fixed in 4.4.4 - System.ServiceModel.NetTcp (NuGet): affected from 4.5.0; fixed in 4.5.3 - System.ServiceModel.NetTcp (NuGet): affected from 4.5.0; fixed in 4.5.3 - System.Private.ServiceModel (NuGet): affected from 4.0.0; fixed in 4.1.3 - System.Private.ServiceModel (NuGet): affected from 4.0.0; fixed in 4.1.3 - System.Private.ServiceModel (NuGet): affected from 4.3.0; fixed in 4.3.3 - System.Private.ServiceModel (NuGet): affected from 4.3.0; fixed in 4.3.3 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2018-8356/ (Markdown: https://insights.sbomify.com/CVE-2018-8356/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2018-8356 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-8356 - OSV: https://osv.dev/vulnerability/CVE-2018-8356 --- From sbomify Insights: https://insights.sbomify.com/CVE-2018-8356/ Summaries are generated and may contain mistakes; the official description above is the record.