Microsoft Security Advisory CVE-2025-21171 | .NET Remote Code Execution Vulnerability
Date: 2025-01
Affected: nuget/Microsoft.NetCore.App.Runtime.win-x86, nuget/Microsoft.NetCore.App.Runtime.win-x64, nuget/Microsoft.NetCore.App.Runtime.win-arm64
Attack vector: rce
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2025-21171
CWE: CWE-122
CVSS: 8.1 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

# Microsoft Security Advisory CVE-2025-21171 | .NET Remote Code Execution Vulnerability ## <a name="executive-summary"></a>Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. An attacker could exploit this vulnerability by sending a specially crafted request to the vulnerable web server. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/runtime/issues/111423 ## <a name="mitigation-factors"></a>Mitigation factors Microsoft has not identified any mitigating factors for this vulnerability. ## <a name="affected-software"></a>Affected software * Any .NET 9.0 application running on .NET 9.0.0 or earlier. ## <a name="affected-packages"></a>Affected Packages The vulnerability affects any Microsoft .NET project if it uses any of affected packages versions listed below ### <a name=".NET 9"></a>.NET 9 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- [Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm) | >= 9.0.0, < 9.0.1 | 9.0.1 [Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64) | >= 9.0.0, < 9.0.1 | 9.0.1 [Microsoft.NetCore.App.Runtime.linux


Mitigations:

Architectural layers (MAESTRO):