CVE-2021-1723: ASP.NET Core and Visual Studio Denial of Service Vulnerability
First published: Tue Jan 12 2021(Updated: )
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.
Credit: secure@microsoft.com secure@microsoft.com secure@microsoft.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Microsoft ASP.NET Core | >=3.1<=3.1.10 | |
| Microsoft ASP.NET Core | >=5.0<=5.0.1 | |
| Microsoft Visual Studio 2019 | >=16.0<=16.8 | |
| Fedoraproject Fedora | =32 | |
| Fedoraproject Fedora | =33 | |
| Microsoft Visual Studio 2019 | =16.8 | |
| Microsoft ASP.NET Core | =5.0 | |
| Microsoft Visual Studio 2019 (includes 16.0 - 16.3) | =16.4 | |
| Microsoft ASP.NET Core | =3.1 | |
| Microsoft Visual Studio 2019 (includes 16.0 – 16.6) | =16.7 | |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-arm | =5.0.1 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-x86 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-x86 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-x64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-x64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-arm64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-arm64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-arm | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.win-arm | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.osx-x64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.osx-x64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-x64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-x64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-arm64 | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-arm64 | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-arm | >=5.0.0<5.0.2 | 5.0.2 |
| nuget/Microsoft.AspNetCore.App.Runtime.linux-arm | >=3.1.0<3.1.11 | 3.1.11 |
| nuget/Microsoft.AspNetCore.Server.Kestrel.Core | <2.1.25 | 2.1.25 |
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Reference Links
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1723
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1723 (Advisory)
- https://nvd.nist.gov/vuln/detail/CVE-2021-1723
- https://github.com/dotnet/announcements/issues/170
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3L27CGRVEWUPELNJOGTCW6GLEDBECB4B
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RRXHERXW4KR5WCP76UDW5PC7GX3YQLUW
- https://github.com/advisories/GHSA-242j-2gm6-5rwx (Advisory)
Frequently Asked Questions
What is CVE-2021-1723?
CVE-2021-1723 is a Denial of Service vulnerability in ASP.NET Core and Visual Studio.
What is the severity of CVE-2021-1723?
CVE-2021-1723 has a severity of 7.5 (high).
Which software products are affected by CVE-2021-1723?
ASP.NET Core versions 3.1 to 3.1.10, 5.0 to 5.0.1, and Microsoft Visual Studio 2019 versions 16.0 to 16.8 are affected.
How can I fix CVE-2021-1723?
Apply the necessary updates or patches provided by Microsoft or Fedora Project, depending on the affected software.
Where can I find more information about CVE-2021-1723?
You can find more information about CVE-2021-1723 at the following reference: [link](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1723)
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