CVE-2024-21386

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

.NET Core SDK (reflecting any global.json):

 Version:   6.0.200
 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\6.0.300\

Host (useful for support):

  Version: 6.0.5
  Commit:  8473146e7d

.NET Core SDKs installed:

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

.NET Core runtimes installed:

  Microsoft.AspNetCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2024-21386 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.0.27, 7.0.16, 8.0.2); upgrading removes the vulnerable code path.

Kodem intelligence

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1. What is CVE-2024-21386? CVE-2024-21386 is a high-severity uncontrolled resource consumption vulnerability in Microsoft.AspNetCore.App.Runtime.linux-arm (nuget), affecting versions <= 6.0.26. It is fixed in 6.0.27, 7.0.16, 8.0.2. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2024-21386? CVE-2024-21386 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2024-21386?
   • Microsoft.AspNetCore.App.Runtime.linux-arm (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.linux-arm64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.linux-x64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.osx-arm64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.osx-x64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.win-arm (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.win-arm64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.win-x64 (nuget) (versions <= 6.0.26)
   • Microsoft.AspNetCore.App.Runtime.win-x86 (nuget) (versions <= 6.0.26)
4. Is there a fix for CVE-2024-21386? Yes. CVE-2024-21386 is fixed in 6.0.27, 7.0.16, 8.0.2. Upgrade to this version or later.
5. Is CVE-2024-21386 exploitable, and should I be worried? Whether CVE-2024-21386 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-21386 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-21386?
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 6.0.27 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 7.0.16 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 8.0.2 or later
   • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 8.0.2 or later

Other vulnerabilities in Microsoft.AspNetCore.App.Runtime.linux-arm