CVE-2021-1723

HIGH

ASP.NET Core and Visual Studio Denial of Service Vulnerability

Published May 24, 2022Updated November 29, 2024Source: osv

Summary

A denial-of-service vulnerability exists in the way Kestrel parses HTTP/2 requests. The security update addresses the vulnerability by fixing the way the Kestrel parses HTTP/2 requests. Users are advised to upgrade.

Remediation

Upgrade to the fixed version using your package manager.

NuGet

Update Microsoft.AspNetCore.Server.Kestrel.Core to 2.1.25 or later

dotnet add package Microsoft.AspNetCore.Server.Kestrel.Core --version 2.1.25

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-x64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-x64 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-arm to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-x64 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-x64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-x64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-arm to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-arm to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-arm --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-arm64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-arm64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-x86 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-x86 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-arm64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-arm64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-arm64 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-arm64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.osx-x64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.osx-x64 --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-x64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-arm --version 5.0.2

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-arm to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-arm --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.osx-x64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.osx-x64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.win-x86 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-x86 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-x64 to 3.1.11 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-x64 --version 3.1.11

NuGet

Update Microsoft.AspNetCore.App.Runtime.linux-x64 to 5.0.2 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-x64 --version 5.0.2

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (22)

Package	Ecosystem	Affected	Fixed In
Microsoft.AspNetCore.Server.Kestrel.Core	nuget	0.0.1-alpha, 2.0.0, 2.0.0-preview1-final, 2.0.0-preview2-final (+12 more)	2.1.25
Microsoft.AspNetCore.App.Runtime.win-x64	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.linux-arm	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.linux-musl-x64	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.win-x64	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.linux-arm	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.win-arm	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.win-arm64	nuget	3.1.10, 3.1.5, 3.1.6, 3.1.7 (+2 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.win-x86	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.linux-arm64	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.win-arm64	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.linux-arm64	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.osx-x64	nuget	5.0.0, 5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.linux-musl-x64	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.linux-musl-arm	nuget	5.0.1	5.0.2
Microsoft.AspNetCore.App.Runtime.win-arm	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.osx-x64	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.win-x86	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.linux-x64	nuget	3.1.0, 3.1.1, 3.1.10, 3.1.2 (+7 more)	3.1.11
Microsoft.AspNetCore.App.Runtime.linux-x64	nuget	5.0.0, 5.0.1	5.0.2

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 7.5 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Frequently Asked Questions

What is CVE-2021-1723?: ASP.NET Core and Visual Studio Denial of Service Vulnerability This vulnerability has been assigned a severity rating of HIGH (CVSS score: 7.5/10).
How do I check if my project is affected by CVE-2021-1723?: CVE-2021-1723 affects Microsoft.AspNetCore.Server.Kestrel.Core, Microsoft.AspNetCore.App.Runtime.win-x64 and Microsoft.AspNetCore.App.Runtime.linux-arm (and 9 more). Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2021-1723 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

7.5

High exploitability or significant impact. Prioritize remediation within days.

Also Known As

GHSA-242j-2gm6-5rwx

BIT-aspnet-core-2021-1723

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