ASP.NET Core Denial of Service VulnerabilityGHSA-3cf7-7wq6-8842
HIGHGHSA-3cf7-7wq6-8842 is a high-severity (CVSS 7.5) vulnerability in Microsoft.AspNetCore.App.Runtime.linux-arm. A fix is available for Microsoft.AspNetCore.App.Runtime.linux-arm — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
Microsoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-x64.NETMicrosoft.AspNetCore.App.Runtime.osx-x64.NETMicrosoft.AspNetCore.App.Runtime.win-arm.NETMicrosoft.AspNetCore.App.Runtime.win-x64+1 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
A denial of service vulnerability exists when ASP.NET Core improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against an ASP.NET Core web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the ASP.NET Core application. The update addresses the vulnerability by correcting how the ASP.NET Core web application handles web requests.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-arm | ≥ 3.1.0&&< 3.1.4 | 3.1.4dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 3.1.4 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-arm64 | ≥ 3.1.0&&< 3.1.4 | 3.1.4dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 3.1.4 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | ≥ 3.1.0&&< 3.1.4 | 3.1.4dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 --version 3.1.4 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | ≥ 3.1.0&&< 3.1.4 | 3.1.4dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-x64 --version 3.1.4 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-x64 | ≥ 3.1.0&&< 3.1.4 | 3.1.4dotnet add package Microsoft.AspNetCore.App.Runtime.linux-x64 --version 3.1.4 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.osx-x64 | ≥ 3.1.0&&< 3.1.4 | 3.1.4dotnet add package Microsoft.AspNetCore.App.Runtime.osx-x64 --version 3.1.4 |
Affected Products
asp.net coremicrosoftvisual studio 2017microsoftvisual studio 2019microsoftDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.App.Runtime.linux-arm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.AspNetCore.App.Runtime.linux-arm to 3.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3cf7-7wq6-8842 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| .NET Core on Red Hat Enterprise Linux | rh-dotnet31-dotnet-0:3.1.104-2.el7 | RHSA-2020:2249 |
| Red Hat Enterprise Linux 8 | dotnet3.1-0:3.1.104-2.el8_2 | RHSA-2020:2250 |
Frequently Asked Questions
Is GHSA-3cf7-7wq6-8842 in your dependencies?
Find it across NuGet, including transitive dependencies.