CVE-2020-1597 — ASP.NET Core Denial of Service Vulnerability

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 products

Vendor	Product	Affected	Fixed
Microsoft	ASP.NET Core 2.1	2.0 – < publication	publication
Microsoft	ASP.NET Core 3.1	3.0 – < publication	publication
Microsoft	Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3)	16.0 – < publication	publication
Microsoft	Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8)	15.9.0 – < publication	publication
Microsoft	Microsoft Visual Studio 2019 version 16.0	16.0 – < publication	publication
Microsoft	Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6)	16.0.0 – < publication	publication

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Red Hat

Security tracker ↗

Release	Package	Fixed in	Advisory
RHEL 8	dotnet +4	3.1.107-1.el8_2	RHSA-2020:3422
RHEL 8	dotnet-host +6	3.1.7-1.el8_2	RHSA-2020:3422

Show 1 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
Red Hat Rhel Dotnet 3	rh-dotnet31-dotnet +3	3.1.107-1.el7	RHSA-2020:3421
Red Hat Rhel Dotnet 3	rh-dotnet31-dotnet-host +6	3.1.7-1.el7	RHSA-2020:3421

Oracle Linux

Release	Package	Fixed in	Advisory
Oracle Linux 8	dotnet +3	3.1.107-1.0.1.el8_2	ELSA-2020-3422
Oracle Linux 8	dotnet-host +6	3.1.7-1.0.1.el8_2	ELSA-2020-3422

Affected packages

Ecosystem	Package	Affected	Fixed	Record
NuGet	Microsoft.AspNetCore.All	>= 2.1.0, < 2.1.21	2.1.21	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App	>= 2.1.0, < 2.1.21	2.1.21	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.linux-arm	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.linux-arm64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.linux-musl-arm64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.linux-musl-x64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.linux-x64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.osx-x64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.win-arm	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.win-arm64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.win-x64	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx
NuGet	Microsoft.AspNetCore.App.Runtime.win-x86	>= 3.1.0, < 3.1.7	3.1.7	GHSA-f8qx-mjcq-wfgx

Advisories 3

RHSA-2020:3421 Red Hat Security Advisory: .NET Core 3.1 security and bugfix update for Red Hat Enterprise Linux Red Hat Security Advisories (RHSA) · Feb 24, 2026
RHSA-2020:3422 Red Hat Security Advisory: .NET Core 3.1 security and bugfix update Red Hat Security Advisories (RHSA) · Feb 24, 2026
ELSA-2020-3422 Important: .NET Core 3.1 security and bugfix update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 16, 2020

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1597
FEDORA-2020-cad5d17c6d vendor-advisory
FEDORA-2020-9ddf1aa50b vendor-advisory