TI-2021-01439 Aliases CVE-2021-1723 GHSA-242j-2gm6-5rwx

ASP.NET Core and Visual Studio Denial of Service Vulnerability

MEDIUM 47Published 2021-01-12 · Updated 2026-05-28

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

ASP.NET Core and Visual Studio Denial of Service Vulnerability

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.05298 92nd percentileScored 2026-11-07

Fix Fixed ASP.NET Core 3.1 (Microsoft): publicationASP.NET Core 5.0 (Microsoft): publication+15 more productsRed Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Microsoft	ASP.NET Core 3.1	3.0 to before publication	publication	Patch available	CNA
Microsoft	ASP.NET Core 5.0	5.0 to before publication	publication	Patch available	CNA
Microsoft	Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3)	16.0 to before publication	publication	Patch available	CNA
Microsoft	Microsoft Visual Studio 2019 version 16.8	16.0 to before publication	publication	Patch available	CNA
Microsoft	Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6)	16.0.0 to before publication	publication	Patch available	CNA
—	Microsoft.AspNetCore.Server.Kestrel.Core (NuGet)	before 2.1.25	2.1.25	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-arm (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-arm (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet)	3.1.0 to before 3.1.11	3.1.11	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet)	5.0.0 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx
—	Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet)	5.0.1 to before 5.0.2	5.0.2	Patch available	GHSA-242j-2gm6-5rwx

ASP.NET Core 3.1 VendorMicrosoft Affected 3.0 to before publication Fixed in publication Patch available CNA
ASP.NET Core 5.0 VendorMicrosoft Affected 5.0 to before publication Fixed in publication Patch available CNA
Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3) VendorMicrosoft Affected 16.0 to before publication Fixed in publication Patch available CNA
Microsoft Visual Studio 2019 version 16.8 VendorMicrosoft Affected 16.0 to before publication Fixed in publication Patch available CNA
Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) VendorMicrosoft Affected 16.0.0 to before publication Fixed in publication Patch available CNA
Microsoft.AspNetCore.Server.Kestrel.Core (NuGet) Vendor— Affected before 2.1.25 Fixed in 2.1.25 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) Vendor— Affected 3.1.0 to before 3.1.11 Fixed in 3.1.11 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) Vendor— Affected 5.0.0 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx
Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) Vendor— Affected 5.0.1 to before 5.0.2 Fixed in 5.0.2 Patch available GHSA-242j-2gm6-5rwx

CPE configurations NVD · 4

CPE	Versions	Role	Vendor
cpe:2.3:a:microsoft:asp.net_core::::::::	3.1 – 3.1.10; 5.0 – 5.0.1	Vulnerable	Microsoft
cpe:2.3:a:microsoft:visual_studio_2019::::::::	16.0 – 16.8	Vulnerable	Microsoft
cpe:2.3:o:fedoraproject:fedora:32:::::::*	32	Vulnerable	Fedoraproject
cpe:2.3:o:fedoraproject:fedora:33:::::::*	33	Vulnerable	Fedoraproject

cpe:2.3:a:microsoft:asp.net_core:*:*:*:*:*:*:*:* Versions 3.1 – 3.1.10; 5.0 – 5.0.1 Vulnerable ·Microsoft
cpe:2.3:a:microsoft:visual_studio_2019:*:*:*:*:*:*:*:* Versions 16.0 – 16.8 Vulnerable ·Microsoft
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject

Remediation

Fix · CNA ASP.NET Core 3.1 (Microsoft) Fixed in publication
Fix · CNA ASP.NET Core 5.0 (Microsoft) Fixed in publication
Fix · CNA Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3) (Microsoft) Fixed in publication
Fix · CNA Microsoft Visual Studio 2019 version 16.8 (Microsoft) Fixed in publication
Fix · CNA Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) (Microsoft) Fixed in publication
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.Server.Kestrel.Core (NuGet) Fixed in 2.1.25 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) Fixed in 3.1.11 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) Fixed in 5.0.2 Advisory →
Fix · GHSA-242j-2gm6-5rwx Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) Fixed in 5.0.2 Advisory →

Red Hat 4 advisories

RHSA-2021:0114 Released 2021-01-13 · Red Hat rating Important
.NET Core 3.1 on Red Hat Enterprise Linux security and bugfix update
- .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.11-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.11-1.el7_9, rh-dotnet31-dotnet-3.1.111-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.11-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.11-1.el7_9, rh-dotnet31-dotnet-3.1.111-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.11-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.11-1.el7_9, rh-dotnet31-dotnet-3.1.111-1.el7_9 +8
RHSA-2021:0094 Released 2021-01-13 · Red Hat rating Important
dotnet5.0 security and bugfix update
- Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-5.0-5.0.2-2.el8_3, aspnetcore-targeting-pack-5.0-5.0.2-2.el8_3, dotnet-5.0.102-2.el8_3 +9
RHSA-2021:0096 Released 2021-01-13 · Red Hat rating Important
.NET 5.0 on Red Hat Enterprise Linux security and bugfix update
- .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.2-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.2-1.el7_9, rh-dotnet50-dotnet-5.0.102-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.2-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.2-1.el7_9, rh-dotnet50-dotnet-5.0.102-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.2-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.2-1.el7_9, rh-dotnet50-dotnet-5.0.102-1.el7_9 +8

Show 1 more Red Hat advisories

RHSA-2021:0095 Released 2021-01-13 · Red Hat rating Important
dotnet3.1 security and bugfix update
- Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-3.1-3.1.11-1.el8_3, aspnetcore-targeting-pack-3.1-3.1.11-1.el8_3, dotnet-apphost-pack-3.1-3.1.11-1.el8_3 +6

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Product	Status	Plan or fix
.NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)	Fixed	RHSA-2021:0096, RHSA-2021:0114
.NET Core on Red Hat Enterprise Linux Server (v. 7)	Fixed	RHSA-2021:0096, RHSA-2021:0114
.NET Core on Red Hat Enterprise Linux Workstation (v. 7)	Fixed	RHSA-2021:0096, RHSA-2021:0114
Red Hat Enterprise Linux AppStream (v. 8)	Fixed	RHSA-2021:0094, RHSA-2021:0095

Not affected: 3 products

.NET Core 2.1 on Red Hat Enterprise Linux
Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 9

Timeline

2026-10-02 Threatist record created from CVE-2021-1723
2026-10-03 Alias added: GHSA-242j-2gm6-5rwx

References

Advisory 2

Other 3

TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
TI-2023-19596 .NET and Visual Studio Denial of Service Vulnerability KEVCVSS 3.1HIGH 7.5
TI-2025-34970 ASP.NET Security Feature Bypass Vulnerability CVSS 3.1CRITICAL 9.9
TI-2024-14164 .NET Denial of Service Vulnerability CVSS 3.1HIGH 7.5
TI-2023-18092 ASP.NET Core Denial of Service Vulnerability CVSS 3.1HIGH 8.2
TI-2023-18392 ASP.NET Core Security Feature Bypass Vulnerability CVSS 3.1MEDIUM 6.2

See all 40 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences

ASP.NET Core and Visual Studio Denial of Service Vulnerability

Key facts

Summary

Why it matters now

SSVC decision points

Affected products

CPE configurations NVD · 4

Remediation

Red Hat 4 advisories

Vendor assessments

Red Hat

Timeline

References

Advisory 2

Other 3

More Microsoft Asp.net Core vulnerabilities

Sources