CVE-2024-43499

.NET and Visual Studio Denial of Service Vulnerability

.NET and Visual Studio Denial of Service Vulnerability

Microsoft Security Advisory CVE-2024-43499 | .NET Denial of Service 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.

The NrbfDecoder component in .NET 9 contains a denial of service vulnerability due to incorrect input validation.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/333

<a name="mitigation-factors"></a>Mitigation factors

Applications that do not use the NrbfDecoder component are not affected by this vulnerability. By default, .NET console apps and web apps do not reference this component.

<a name="affected-software"></a>Affected software

• Any .NET 9.0 application running on .NET 9.0.0.RC.2 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 9"></a>.NET 9

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- System.Formats.Nrbf | <9.0.0 | 9.0.0

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?

1. To fix the issue please install the latest version of .NET 9.0 . 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.
2. If your application references the vulnerable package, update the package reference to the patched version.

Note: You may need to take both actions. Upgrading to 9.0 GA is not by itself sufficient to resolve the vulnerability, since you could still be pulling in the vulnerable package by reference.

• If you have .NET 8.0 or greater installed, you can list the versions you have installed by running the dotnet --info command. You will see output like the following;

.NET Core SDK (reflecting any global.json):


 Version:   8.0.200
 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: 8.0.3
  Commit:  8473146e7d

.NET Core SDKs installed:

  8.0.200 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:

  Microsoft.NetCore.App 8.0.3 [C:\Program Files\dotnet\shared\Microsoft.NetCore.App]
  Microsoft.AspNetCore.App 8.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.WindowsDesktop.App 8.0.3 [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 9.0, you should download and install .NET 9.0 Runtime or .NET 9.0.100 SDK (for Visual Studio 2022 v17.12 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/9.0.

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 9.0 or .NET 8.0, please email details to [email protected]. Reports may qualify for the Microsoft .NET Core & .NET 5…

.NET and Visual Studio Denial of Service Vulnerability

.NET and Visual Studio Denial of Service Vulnerability

Microsoft Security Advisory CVE-2024-43499 | .NET Denial of Service 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.

The NrbfDecoder component in .NET 9 contains a denial of service vulnerability due to incorrect input validation.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/333

<a name="mitigation-factors"></a>Mitigation factors

Applications that do not use the NrbfDecoder component are not affected by this vulnerability. By default, .NET console apps and web apps do not reference this component.

<a name="affected-software"></a>Affected software

• Any .NET 9.0 application running on .NET 9.0.0.RC.2 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 9"></a>.NET 9

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- System.Formats.Nrbf | <9.0.0 | 9.0.0

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?

1. To fix the issue please install the latest version of .NET 9.0 . 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.
2. If your application references the vulnerable package, update the package reference to the patched version.

Note: You may need to take both actions. Upgrading to 9.0 GA is not by itself sufficient to resolve the vulnerability, since you could still be pulling in the vulnerable package by reference.

• If you have .NET 8.0 or greater installed, you can list the versions you have installed by running the dotnet --info command. You will see output like the following;

.NET Core SDK (reflecting any global.json):


 Version:   8.0.200
 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: 8.0.3
  Commit:  8473146e7d

.NET Core SDKs installed:

  8.0.200 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:

  Microsoft.NetCore.App 8.0.3 [C:\Program Files\dotnet\shared\Microsoft.NetCore.App]
  Microsoft.AspNetCore.App 8.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.WindowsDesktop.App 8.0.3 [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 9.0, you should download and install .NET 9.0 Runtime or .NET 9.0.100 SDK (for Visual Studio 2022 v17.12 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/9.0.

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 9.0 or .NET 8.0, please email details to [email protected]. Reports may qualify for the Microsoft .NET Core & .NET 5…