CVE-2024-21386

.NET Denial of Service Vulnerability

Microsoft Security Advisory CVE-2024-21386: .NET Denial of Service Vulnerability

Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET 6.0, ASP.NET 7.0 and, ASP.NET 8.0 . This advisory also provides guidance on what developers can do to update their applications to address this vulnerability.

A vulnerability exists in ASP.NET applications using SignalR where a malicious client can result in a denial-of-service.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/295

Mitigation factors

Microsoft has not identified any mitigating factors for this vulnerability.

Affected software

• Any .NET 6.0 application running on .NET 6.0.26 or earlier.
• Any .NET 7.0 application running on .NET 7.0.15 or earlier.
• Any .NET 8.0 application running on .NET 8.0.1 or earlier.

Affected Packages

The vulnerability affects any Microsoft .NET Core project if it uses any of affected packages versions listed below

ASP.NET 6.0

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.linux-arm64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.linux-x64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.osx-arm64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.osx-x64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.win-arm | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.win-arm64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.win-x64 | <= 6.0.26 | 6.0.27 Microsoft.AspNetCore.App.Runtime.win-x86 | <= 6.0.26 | 6.0.27

ASP.NET 7.0

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | <= 7.0.15 | 7.0.16 Microsoft.AspNetCore.App.Runtime.linux-arm64 | <= 7.0.15 | 7.0.16 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | <= 7.0.15 | 7.0.16 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | <= 7.0.15 | 7.0.16 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | <= 7.0.15 | 7.0.16…

.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 7.0.119 and .NET Runtime 7.0.19.

Security Fix(es):

• dotnet: stack buffer overrun in Double Parse (CVE-2024-30045)

• dotnet: denial of service in ASP.NET Core due to deadlock in Http2OutputProducer.Stop() (CVE-2024-30046)

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 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 7.0.116 and .NET Runtime 7.0.16.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)
• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 7.0.116 and .NET Runtime 7.0.16.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)
• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 6.0.127 and .NET Runtime 6.0.27.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)
• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 6.0.127 and .NET Runtime 6.0.27.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)
• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 8.0.102 and .NET Runtime 8.0.2.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)
• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 8.0.102 and .NET Runtime 8.0.2.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)
• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 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 7.0.116 and .NET Runtime 7.0.16.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)

• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 8.0.102 and .NET Runtime 8.0.2.

Security Fix(es):

• dotnet: Denial of Service in SignalR server (CVE-2024-21386)

• dotnet: Denial of Service in X509Certificate2 (CVE-2024-21404)

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 .NET with SignalR did not properly handle malicious clients. An attacker could possibly use this issue to cause a denial of service. (CVE-2024-21386)

Bahaa Naamneh discovered that .NET with OpenSSL support did not properly parse X509 certificates. An attacker could possibly use this issue to cause a denial of service. (CVE-2024-21404)