CVE-2024-21409 — Microsoft.WindowsDesktop.…
HIGHCVE-2024-21409 is a high-severity (CVSS 7.3) Use After Free vulnerability in Microsoft.WindowsDesktop.App.Runtime.win-arm64. A fix is available for Microsoft.WindowsDesktop.App.Runtime.win-arm64 — see the affected versions and patch details below.
.NET Elevation of Privilege Vulnerability
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-21409.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2024-21409 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 383,485 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
Microsoft.WindowsDesktop.App.Runtime.win-arm64.NETMicrosoft.WindowsDesktop.App.Runtime.win-arm64.NETMicrosoft.WindowsDesktop.App.Runtime.win-arm64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x86.NETMicrosoft.WindowsDesktop.App.Runtime.win-x86+1 moreReal-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
Microsoft Security Advisory CVE-2024-21409 | .NET Elevation of Privilege Vulnerability
<a name="executive-summary"></a>Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 6.0, .NET 7.0 ,and .NET 8.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
A use-after-free vulnerability exists in WPF which may result in Elevation of Privilege when viewing untrusted documents. This is a Windows only vulnerability.
Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/303
<a name="mitigation-factors"></a>Mitigation factors
This vulnerability affects only WPF-based applications.
<a name="affected-software"></a>Affected software
- Any .NET 6.0 application running on .NET 6.0.28 or earlier.
- Any .NET 7.0 application running on .NET 7.0.17 or earlier.
- Any .NET 8.0 application running on .NET 8.0.3 or earlier.
<a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET Core project if it uses any of affected packages versions listed below
<a name=".NET 7"></a>.NET 6.0
| Package name | Affected version | Patched version |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | < = 6.0.28 | 6.0.29 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | < = 6.0.28 | 6.0.29 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | < = 6.0.28 | 6.0.29 |
<a name=".NET 7"></a>.NET 7.0
| Package name | Affected version | Patched version |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | <= 7.0.17 | 7.0.18 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | <= 7.0.17 | 7.0.18 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | <= 7.0.17 | 7.0.18 |
<a name=".NET 7"></a>.NET 8.0
| Package name | Affected version | Patched version |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | <= 8.0.3 | 8.0.4 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | <= 8.0.3 | 8.0.4 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | <= 8.0.3 | 8.0.4 |
Advisory FAQ
<a name="how-affected"></a>How do I know if I am affected?
If you have a runtime or SDK with a version listed, or an affected package listed in affected software or affected packages, you're exposed to the vulnerability.
<a name="how-fix"></a>How do I fix the issue?
- To fix the issue please install the latest version of .NET 8.0 or .NET 7.0 or .NET 6.0. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs.
- If you have .NET 6.0 or greater installed, you can list the versions you have installed by running the
dotnet --infocommand. You will see output like the following;
.NET Core SDK (reflecting any global.json):
Version: 8.0.204
Commit: 8473146e7d
Runtime Environment:
OS Name: Windows
OS Version: 10.0.18363
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\6.0.300\
Host (useful for support):
Version: 8.0.4
Commit: 8473146e7d
.NET Core SDKs installed:
8.0.204 [C:\Program Files\dotnet\sdk]
.NET Core runtimes installed:
Microsoft.AspWindowsDesktop.App 8.0.4 [C:\Program Files\dotnet\shared\Microsoft.AspWindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download
- If you're using .NET 8.0, you should download and install .NET 8.0.4 Runtime or .NET 8.0.204 SDK (for Visual Studio 2022 v17.8) from https://dotnet.microsoft.com/download/dotnet-core/8.0.
- If you're using .NET 7.0, you should download and install Runtime 7.0.18 or SDK 7.0.118 (for Visual Studio 2022 v17.4) from https://dotnet.microsoft.com/download/dotnet-core/7.0.
- If you're using .NET 6.0, you should download and install Runtime 6.0.29 or SDK 6.0.129 from https://dotnet.microsoft.com/download/dotnet-core/6.0.
.NET 6.0, .NET 7.0 and, .NET 8.0 updates are also available from Microsoft Update. To access this either type "Check for updates" in your Windows search, or open Settings, choose Update & Security and then click Check for Updates.
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.
Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.
Other Information
Reporting Security Issues
If you have found a potential security issue in .NET 8.0 or .NET 7.0 or .NET 6.0, please email details to [email protected]. Reports may qualify for the Microsoft .NET Core & .NET 5 Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.
Support
You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime and https://github.com/dotnet/aspnet/. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.
Disclaimer
The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
External Links
Revisions
V1.0 (April 09, 2024): Advisory published.
Version 1.0
Last Updated 2024-04-09
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.WindowsDesktop.App.Runtime.win-arm64 | all versions | 6.0.29dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 6.0.29 |
| .NETNuGet | Microsoft.WindowsDesktop.App.Runtime.win-arm64 | ≥ 8.0.0&&< 8.0.4 | 8.0.4dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 8.0.4 |
| .NETNuGet | Microsoft.WindowsDesktop.App.Runtime.win-arm64 | ≥ 7.0.0&&< 7.0.18 | 7.0.18dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 7.0.18 |
| .NETNuGet | Microsoft.WindowsDesktop.App.Runtime.win-x64 | all versions | 6.0.29dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 6.0.29 |
| .NETNuGet | Microsoft.WindowsDesktop.App.Runtime.win-x64 | ≥ 8.0.0&&< 8.0.4 | 8.0.4dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 8.0.4 |
| .NETNuGet | Microsoft.WindowsDesktop.App.Runtime.win-x64 | ≥ 7.0.0&&< 7.0.18 | 7.0.18dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 7.0.18 |
Affected Products
.netmicrosoft.net frameworkmicrosoftpowershellmicrosoftvisual studio 2022microsoftDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.WindowsDesktop.App.Runtime.win-arm64, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.WindowsDesktop.App.Runtime.win-arm64 to 6.0.29 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21409 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Frequently Asked Questions
Is CVE-2024-21409 in your dependencies?
Find it across NuGet, including transitive dependencies.