# CVE-2023-21538: .NET Denial of Service Vulnerability - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C`) - **Exploited in the wild:** Not known - **Fix available:** Yes - **Published:** 10 Jan 2023 - **Updated:** 1 Jan 2025 - **Also known as:** ALSA-2023:0077, ALSA-2023:0079, BIT-dotnet-2023-21538, BIT-dotnet-sdk-2023-21538, BIT-powershell-2023-21538, CLEANSTART-2024-MV63689, GHSA-8f7f-vqg5-jrv9, RHSA-2023:0077, RHSA-2023:0078, RHSA-2023:0079, RLSA-2023:0077, RLSA-2023:0079, UBUNTU-CVE-2023-21538, USN-5798-1 ## What is CVE-2023-21538? CVE-2023-21538 is a high-severity vulnerability in Fedoraproject Fedora, published on 10 Jan 2023. ### Official description .NET Denial of Service Vulnerability Weakness: CWE-502 (Deserialization of Untrusted Data) ## Which versions are affected by CVE-2023-21538? 27 open source packages ship an affected version, including Microsoft.NETCore.App.Runtime.linux-arm, dotnet and dotnet-sdk. It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `Microsoft.NETCore.App.Runtime.linux-arm` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-arm` | NuGet | From 6.0.0 | 6.0.13 | | `dotnet` | Bitnami | From 6.0.0 | 6.0.1 | | `dotnet-sdk` | Bitnami | From 6.0.0 | 6.0.1 | | `powershell` | Bitnami | From 7.2.0 to 7.2.0 | None | | `Microsoft.NETCore.App.Runtime.linux-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-musl-arm` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-musl-arm` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-musl-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-musl-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-musl-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-musl-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.linux-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.osx-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.osx-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.osx-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.osx-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-arm` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-arm` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-arm64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-x64` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-x86` | NuGet | From 6.0.0 | 6.0.13 | | `Microsoft.NETCore.App.Runtime.win-x86` | NuGet | From 6.0.0 | 6.0.13 | | `aspnetcore-runtime-6.0` | AlmaLinux:8 | All versions | 6.0.13-1.el8_7 | | `aspnetcore-targeting-pack-6.0` | AlmaLinux:8 | All versions | 6.0.13-1.el8_7 | | `dotnet-apphost-pack-6.0` | AlmaLinux:8 | All versions | 6.0.13-1.el8_7 | | `dotnet-hostfxr-6.0` | AlmaLinux:8 | All versions | 6.0.13-1.el8_7 | | `dotnet-runtime-6.0` | AlmaLinux:8 | All versions | 6.0.13-1.el8_7 | | `dotnet-sdk-6.0` | AlmaLinux:8 | All versions | 6.0.113-1.el8_7 | | `dotnet-sdk-6.0-source-built-artifacts` | AlmaLinux:8 | All versions | 6.0.113-1.el8_7 | | `dotnet-targeting-pack-6.0` | AlmaLinux:8 | All versions | 6.0.13-1.el8_7 | | `dotnet-templates-6.0` | AlmaLinux:8 | All versions | 6.0.113-1.el8_7 | | `aspnetcore-runtime-6.0` | AlmaLinux:9 | All versions | 6.0.13-1.el9_1 | | `aspnetcore-targeting-pack-6.0` | AlmaLinux:9 | All versions | 6.0.13-1.el9_1 | | `dotnet-apphost-pack-6.0` | AlmaLinux:9 | All versions | 6.0.13-1.el9_1 | | `dotnet-hostfxr-6.0` | AlmaLinux:9 | All versions | 6.0.13-1.el9_1 | Products: Fedoraproject Fedora, Microsoft .Net, Microsoft Powershell. ## How do I fix CVE-2023-21538? Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 6.0.13 or later. ## Is CVE-2023-21538 being exploited? There is no known exploitation of CVE-2023-21538 in the wild and no public exploit code. ## Other vulnerabilities in Fedoraproject Fedora - [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild) - [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild) - [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild) - [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild) - [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-21538 and fix it if it is affected. What it is: CVE-2023-21538 is a high-severity vulnerability in Fedoraproject Fedora, published on 10 Jan 2023. Exploitation: There is no known exploitation of CVE-2023-21538 in the wild and no public exploit code. Affected packages and fixed versions: - Microsoft.NETCore.App.Runtime.linux-arm (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-arm (NuGet): affected from 6.0.0; fixed in 6.0.13 - dotnet (Bitnami): affected from 6.0.0; fixed in 6.0.1 - dotnet-sdk (Bitnami): affected from 6.0.0; fixed in 6.0.1 - powershell (Bitnami): affected from 7.2.0 up to 7.2.0; no fix listed - Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet): affected from 6.0.0; fixed in 6.0.13 - Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet): affected from 6.0.0; fixed in 6.0.13 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-2023-21538/ (Markdown: https://insights.sbomify.com/CVE-2023-21538/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-21538 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-21538 - OSV: https://osv.dev/vulnerability/CVE-2023-21538 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-21538/ Summaries are generated and may contain mistakes; the official description above is the record.