CVE-2024-21319

A Denial of Service vulnerability exists in ASP.NET Core project templates which utilize JWT-based authentication tokens. This vulnerability allows an unauthenticated client to consume arbitrarily large amounts of server memory, potentially triggering an out-of-memory condition on the server and making the server no longer able to respond to legitimate requests.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/290

Mitigation factors

This impacts only .NET Core-based projects that were created using any version of project templates listed in affected software. Other project templates e.g., console applications, MAUI applications, Windows Forms or WPF applications, are not affected.

Affected software

This impacts only .NET Core-based projects that were created using any version of the below project templates.

• ASP.NET Core Web App (Model-View-Controller)
• ASP.NET Core Web API
• ASP.NET Core Web App (Razor Pages)
• Blazor Server App
• Blazor WebAssembly App

Advisory FAQ

How do I know if I am affected?

If you are you using project templates listed in affected software, you may be exposed to the vulnerability.

How do I fix the issue?

For existing projects:

If you ever created any of these projects via the dotnet new command or via Visual Studio's File -> New Project gesture, and if you enabled federated authentication at project creation time, your project may be vulnerable. To remediate the vulnerability, use your package manager to update any references you may have to the Microsoft.AspNetCore.Authentication.JwtBearer, Microsoft.AspNetCore.Authentication.OpenIdConnect, and Microsoft.IdentityModel.JsonWebTokens packages to their respective latest versions.

• Microsoft.AspNetCore.Authentication.JwtBearer
• Microsoft.AspNetCore.Authentication.OpenIdConnect

If your project does not reference any of those three packages, you are not exposed to this vulnerability.

For new projects:

To remediate this issue please update to the latest SDK listed below. Simply installing the SDK update is not sufficient to remediate projects already-created / already-deployed projects which existed prior to this update being released.

• To fix the issue please install the latest version of .NET 6.0 or .NET 7.0. 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 are using one of the affected packages, please update to the patched version listed above.
• If you have .NET 6.0 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:   7.0.200
 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\7.0.300\

Host (useful for support):

  Version: 76.0.5
  Commit:  8473146e7d

.NET Core SDKs installed:

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

.NET Core runtimes installed:

  Microsoft.AspNetCore.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 7.0.5 [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 8.0.101 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 .NET SDK 7.0.115 (for Visual Studio 2022 v17.4)…

Microsoft Identity Denial of service 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 8.0.101 and .NET Runtime 8.0.1.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)
• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)
• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 7.0.115 and .NET Runtime 7.0.15.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)
• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)
• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 8.0.101 and .NET Runtime 8.0.1.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)
• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)
• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 6.0.126 and .NET Runtime 6.0.26.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)
• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)
• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 7.0.115 and .NET Runtime 7.0.15.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)
• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)
• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 6.0.126 and .NET Runtime 6.0.26.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)
• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)
• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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.

Microsoft Identity Denial of service vulnerability

Microsoft Identity Denial of service 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 8.0.101 and .NET Runtime 8.0.1.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)

• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)

• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 7.0.115 and .NET Runtime 7.0.15.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)

• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)

• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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 6.0.126 and .NET Runtime 6.0.26.

Security Fix(es):

• dotnet: Information Disclosure: MD.SqlClient(MDS) & System.data.SQLClient (SDS) (CVE-2024-0056)

• dotnet: X509 Certificates - Validation Bypass across Azure (CVE-2024-0057)

• dotnet: .NET Denial of Service Vulnerability (CVE-2024-21319)

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.

Vishal Mishra and Anita Gaud discovered that .NET did not properly validate X.509 certificates with malformed signatures. An attacker could possibly use this issue to bypass an application's typical authentication logic. (CVE-2024-0057)

Morgan Brown discovered that .NET did not properly handle requests from unauthenticated clients. An attacker could possibly use this issue to cause a denial of service. (CVE-2024-21319)