CVE-2024-38229

Microsoft Security Advisory CVE-2024-38229 | .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 8.0 and .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A vulnerability exists in ASP.NET when closing an HTTP/3 stream while application code is writing to the response body, a race condition may lead to use-after-free.

Note: HTTP/3 is experimental in .NET 6.0. If you are on .NET 6.0 and using HTTP/3, please upgrade to .NET 8.0.10. .NET 6.0 will not receive a security patch for this vulnerability.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/326

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

HTTP/3 support is not enabled by default in ASP.NET Core applications. For more information on how to configure HTTP/3 support please visit https://learn.microsoft.com/aspnet/core/fundamentals/servers/kestrel/http3?view=aspnetcore-8.0#getting-started and https://learn.microsoft.com/aspnet/core/fundamentals/servers/kestrel/endpoints?view=aspnetcore-8.0#configure-http-protocols-in-appsettingsjson.

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

• Any ASP.NET 8.0 application running on .NET 8.0.8 or earlier.
• Any ASP.NET 9.0 application running on .NET 9.0.0.RC.1 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="ASP.NET 9"></a>ASP.NET 9

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.linux-x64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.osx-x64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.win-arm | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.win-arm64 | >=9.0.0-preview.1.24081.5, <= 9.0.0-rc.1.24452.1 | 9.0.0-rc.2.24474.3 Microsoft.AspNetCore.App.Runtime.win-x64 …

.NET and Visual Studio Remote Code Execution Vulnerability

.NET is a managed-software framework. It implements a subset of the .NET framework APIs and several new APIs, and it includes a CLR implementation.

New versions of .NET that address a security vulnerability are now available. The updated versions are .NET SDK 8.0.110 and .NET Runtime 8.0.10.

Security Fix(es):

• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)
• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)
• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)
• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.Security Fix(es):

• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)
• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)
• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)
• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

.NET is a managed-software framework. It implements a subset of the .NET framework APIs and several new APIs, and it includes a CLR implementation.

New versions of .NET that address a security vulnerability are now available. The updated versions are .NET SDK 8.0.110 and .NET Runtime 8.0.10.

Security Fix(es):

• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)
• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)
• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)
• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.Security Fix(es):

• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)
• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)
• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)
• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

.NET and Visual Studio Remote Code Execution Vulnerability

.NET and Visual Studio Remote Code Execution Vulnerability

.NET is a managed-software framework. It implements a subset of the .NET framework APIs and several new APIs, and it includes a CLR implementation.

New versions of .NET that address a security vulnerability are now available. The updated versions are .NET SDK 8.0.110 and .NET Runtime 8.0.10.

Security Fix(es):

• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)
• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)
• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)
• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.Security Fix(es):

• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)

• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)

• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)

• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

.NET is a managed-software framework. It implements a subset of the .NET framework APIs and several new APIs, and it includes a CLR implementation.

New versions of .NET that address a security vulnerability are now available. The updated versions are .NET SDK 8.0.110 and .NET Runtime 8.0.10.

Security Fix(es):

• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)
• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)
• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)
• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.Security Fix(es):

• dotnet: System.IO.Packaging - Multiple DoS vectors in use of SortedList (CVE-2024-43484)

• dotnet: Multiple .NET components susceptible to hash flooding (CVE-2024-43483)

• dotnet: Denial of Service in System.Text.Json (CVE-2024-43485)

• dotnet: kestrel: closing an HTTP/3 stream can cause a race condition and lead to remote code execution (CVE-2024-38229)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Brennan Conroy discovered that the .NET Kestrel web server did not properly handle closing HTTP/3 streams under certain circumstances. An attacker could possibly use this issue to achieve remote code execution. This vulnerability only impacted .NET8. (CVE-2024-38229)

It was discovered that .NET components designed to process malicious input were susceptible to hash flooding attacks. An attacker could possibly use this issue to cause a denial of service, resulting in a crash. (CVE-2024-43483)

It was discovered that the .NET System.IO.Packaging namespace did not properly process SortedList data structures. An attacker could possibly use this issue to cause a denial of service, resulting in a crash. (CVE-2024-43484)

It was discovered that .NET did not properly handle the deserialization of of certain JSON properties. An attacker could possibly use this issue to cause a denial of service, resulting in a crash. (CVE-2024-43485)