CVE-2021-1723: ASP.NET Core and Visual Studio Denial of Service Vulnerability

Quick answers

Is CVE-2021-1723 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2021-1723 being exploited in the wild.

How severe is CVE-2021-1723?

Low severity, with a CVSS score of 3.1, published 24 May 2022.

Which products and versions are affected?

Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11; Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11; Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) ECOSYSTEM:introduced=5.0.1,fixed=5.0.2; Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11; and 8 more.

Is there a fix for CVE-2021-1723?

Yes. Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 5.0.2 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.win-arm (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet): upgrade to 3.1.11 or later; Microsoft.AspNetCore.Server.Kestrel.Core (NuGet): upgrade to 2.1.25 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Am I affected by CVE-2021-1723?

Check whether you run Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

• Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 5.0.2 or later

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

• Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.win-arm (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet): upgrade to 3.1.11 or later

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

• Microsoft.AspNetCore.Server.Kestrel.Core (NuGet): upgrade to 2.1.25 or later

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

Affected products

• Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) ECOSYSTEM:introduced=5.0.1,fixed=5.0.2
• Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) ECOSYSTEM:introduced=3.1.0,fixed=3.1.11
• Microsoft.AspNetCore.Server.Kestrel.Core (NuGet) ECOSYSTEM:introduced=0,fixed=2.1.25

Identifiers

• CVE-2021-1723
• GHSA-242j-2gm6-5rwx