CVE-2020-1161 ASP.NET Core Denial of Service Vulnerability
Remote unauthenticated attackers can cause denial of service in ASP.NET Core applications by sending specially crafted web requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-1161?
CVE-2020-1161 is a high-severity denial of service vulnerability in Microsoft Visual Studio 2017, published on 21 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2020-1161?
19 open source packages ship an affected version, including Microsoft.AspNetCore.App.Runtime.linux-arm, aspnet-core and Microsoft.AspNetCore.App.Runtime.linux-arm64. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.AspNetCore.App.Runtime.linux-arm NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-arm NuGet | From 3.1.0 | 3.1.4 |
aspnet-core Bitnami | From 3.1.0 | 3.1.1 |
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGet | From 3.1.0 | 3.1.4 |
13 more packages
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.osx-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.osx-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.win-arm NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.win-arm NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.win-x86 NuGet | From 3.1.0 | 3.1.4 |
Microsoft.AspNetCore.App.Runtime.win-x86 NuGet | From 3.1.0 | 3.1.4 |
Products include Microsoft Asp.net Core, Microsoft Visual Studio 2017, Microsoft Visual Studio 2019.
How do I fix CVE-2020-1161?
Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 3.1.4 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-1161 being exploited?
There is no known exploitation of CVE-2020-1161 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Visual Studio 2017
- CVE-2025-55315 ASP.NET Security Feature Bypass Vulnerability
- CVE-2026-88092 ASP.NET Core Tampering Vulnerability
- CVE-2026-40372 ASP.NET Core Elevation of Privilege Vulnerability
- CVE-2021-43877 ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability
- CVE-2020-0603 Remote code execution in ASP.NET Core
Sources
Also known as BIT-aspnet-core-2020-1161, GHSA-3cf7-7wq6-8842.