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TI-2021-11420 Aliases CVE-2021-31204

.NET and Visual Studio Elevation of Privilege Vulnerability

Priority LOW 38CWE-269Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-269.

Summary

.NET and Visual Studio Elevation of Privilege Vulnerability

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01192 68th percentileScored 2026-11-07
Fix Fixed .NET Core 3.1 (Microsoft): 3.1.15-servicing.21214.3.NET 5.0 (Microsoft): 5.0.6-servicing.21220.11+4 more productsRed Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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

Affected products

VendorProductAffected versionsFixed inStatusSource
Microsoft.NET Core 3.13.1 to before 3.1.15-servicing.21214.33.1.15-servicing.21214.3Patch availableCNA
Microsoft.NET 5.05.0.0 to before 5.0.6-servicing.21220.115.0.6-servicing.21220.11Patch availableCNA
MicrosoftMicrosoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8)15.0.0 to before publicationpublicationPatch availableCNA
MicrosoftMicrosoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3)16.0 to before publicationpublicationPatch availableCNA
MicrosoftMicrosoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6)16.0.0 to before publicationpublicationPatch availableCNA
MicrosoftVisual Studio 2019 for Mac version 8.98.0 to before publicationpublicationPatch availableCNA
  • .NET Core 3.1 VendorMicrosoft Affected 3.1 to before 3.1.15-servicing.21214.3 Fixed in 3.1.15-servicing.21214.3 Patch available CNA
  • .NET 5.0 VendorMicrosoft Affected 5.0.0 to before 5.0.6-servicing.21220.11 Fixed in 5.0.6-servicing.21220.11 Patch available CNA
  • Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) VendorMicrosoft Affected 15.0.0 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 16.7 (includes 16.0 – 16.6) VendorMicrosoft Affected 16.0.0 to before publication Fixed in publication Patch available CNA
  • Visual Studio 2019 for Mac version 8.9 VendorMicrosoft Affected 8.0 to before publication Fixed in publication Patch available CNA

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*5.0 – 5.0.5VulnerableMicrosoft
cpe:2.3:a:microsoft:.net_core:*:*:*:*:*:*:*:*3.1 – 3.1.14VulnerableMicrosoft
cpe:2.3:a:microsoft:visual_studio_2019:*:*:*:*:*:*:*:*16.0 to before 16.4.22; 16.5.0 to before 16.7.15; 16.8.0 to before 16.9.5VulnerableMicrosoft
cpe:2.3:a:microsoft:visual_studio_2019:8.9:*:*:*:*:macos:*:*8.9VulnerableMicrosoft
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*32VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*33VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
  • cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:* Versions 5.0 – 5.0.5 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:.net_core:*:*:*:*:*:*:*:* Versions 3.1 – 3.1.14 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:visual_studio_2019:*:*:*:*:*:*:*:* Versions 16.0 to before 16.4.22; 16.5.0 to before 16.7.15; 16.8.0 to before 16.9.5 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:visual_studio_2019:8.9:*:*:*:*:macos:*:* Versions 8.9 Vulnerable ·Microsoft
  • cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject

Remediation

  • Fix · CNA .NET Core 3.1 (Microsoft) Fixed in 3.1.15-servicing.21214.3
  • Fix · CNA .NET 5.0 (Microsoft) Fixed in 5.0.6-servicing.21220.11
  • Fix · CNA Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) (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 16.7 (includes 16.0 – 16.6) (Microsoft) Fixed in publication
  • Fix · CNA Visual Studio 2019 for Mac version 8.9 (Microsoft) Fixed in publication

Red Hat 4 advisories

  • RHSA-2021:2036 Released 2021-05-19 · Red Hat rating Important
    dotnet5.0 security and bugfix update
    • Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-5.0-5.0.6-1.el8_4, aspnetcore-targeting-pack-5.0-5.0.6-1.el8_4, dotnet-5.0.203-1.el8_4 +9
  • RHSA-2021:2037 Released 2021-05-19 · Red Hat rating Important
    dotnet3.1 security and bugfix update
    • Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-3.1-3.1.15-1.el8_4, aspnetcore-targeting-pack-3.1-3.1.15-1.el8_4, dotnet-apphost-pack-3.1-3.1.15-1.el8_4 +6
  • RHSA-2021:1547 Released 2021-05-12 · 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-3.1-3.1.15-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.15-1.el7_9, rh-dotnet31-dotnet-3.1.115-1.el7_9 +8
    • .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.15-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.15-1.el7_9, rh-dotnet31-dotnet-3.1.115-1.el7_9 +8
    • .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.15-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.15-1.el7_9, rh-dotnet31-dotnet-3.1.115-1.el7_9 +8
Show 1 more Red Hat advisories
  • RHSA-2021:1546 Released 2021-05-12 · 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-5.0-5.0.6-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.6-1.el7_9, rh-dotnet50-dotnet-5.0.203-1.el7_9 +8
    • .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.6-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.6-1.el7_9, rh-dotnet50-dotnet-5.0.203-1.el7_9 +8
    • .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.6-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.6-1.el7_9, rh-dotnet50-dotnet-5.0.203-1.el7_9 +8

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
.NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)Fixed RHSA-2021:1546, RHSA-2021:1547
.NET Core on Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:1546, RHSA-2021:1547
.NET Core on Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:1546, RHSA-2021:1547
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:2036, RHSA-2021:2037
Not affected: 2 products
  • .NET Core 2.1 on Red Hat Enterprise Linux
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-31204
  2. 2026-10-07 Weakness changed · CISA ADP
  3. 2026-10-07 CISA SSVC decision points changed

References

Patch 1

Advisory 6

  • TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
  • 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-2023-19588 Microsoft QUIC Denial of Service Vulnerability CVSS 3.1HIGH 7.5
  • TI-2024-14152 .NET and Visual Studio Denial of Service Vulnerability CVSS 3.1HIGH 7.5
  • TI-2021-08380 .NET Core Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
See all 129 →

Sources

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