CVE-2021-1721

mediumpriority · track · 18EPSS 0.033 · 89 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

3.34% (89th) EPSS

CVSS 4.3 · medium

Is it mine?

82 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-23

.NET Core and Visual Studio Denial of Service Vulnerability

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 3.7–6.5

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v2.03.7lowAV:N/AC:M/Au:N/C:N/I:N/A:P/E:Usecondary · CVSS-BT (t0sche)

v3.16.5mediumAV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · secure@microsoft.com USexploitability 2.8 · impact 3.6

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · OSV

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · ENISA EU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · NVD / NIST USexploitability 2.8 · impact 3.6

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20US

affected products (82)

Products and version ranges known to be affected.

Microsoft .NET 5.05.0.0 → publicationenisa_euvdEU
Microsoft .NET Core 2.12.1 → publicationenisa_euvdEU
Microsoft .NET Core 3.13.1 → publicationenisa_euvdEU
Microsoft Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8)15.9.0 → publicationenisa_euvdEU
Microsoft Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3)16.0 → publicationenisa_euvdEU
Microsoft Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6)16.0.0 → publicationenisa_euvdEU
Microsoft Microsoft Visual Studio 2019 version 16.816.0 → publicationenisa_euvdEU
Microsoft PowerShell Core 7.07.0.0 → publicationenisa_euvdEU
Microsoft PowerShell Core 7.17.1.0 → publicationenisa_euvdEU
Microsoft Corp .NET Core≤ 3.1fstec_bduRU
Microsoft Corp .NET Core≤ 5.0fstec_bduRU
Microsoft Corp .NET Core≤ 2.1fstec_bduRU
Microsoft Corp Microsoft Visual Studio 201715.0 → 15.8fstec_bduRU
Microsoft Corp Microsoft Visual Studio 2019≤ 16.8fstec_bduRU
Microsoft Corp Microsoft Visual Studio 201916.0 → 16.6fstec_bduRU
Microsoft Corp Microsoft Visual Studio 201916.0 → 16.3fstec_bduRU
Microsoft Corp PowerShell Core≤ 7.1fstec_bduRU
Microsoft Corp PowerShell Core≤ 7.0fstec_bduRU
microsoft .net5.0 → 5.0.2nvdUScpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net core2.1 → 2.1.24nvdUScpe:2.3:a:microsoft:.net_core:*:*:*:*:*:*:*:*

showing 20 of 82

advisories (3)

Vendor and ecosystem advisories describing this.

GHSA-3gp9-h8hw-pxpwDenial of service in .NET core2022-05-24ghsa · osvUS
.NET Core and Visual Studio Denial of Service Vulnerability due to a vulnerability which exists when creating HTTPS web request during X509 certificate chain building.
BIT-dotnet-2021-1721.NET Core and Visual Studio Denial of Service Vulnerability2024-03-06vendor · osvUS
.NET Core and Visual Studio Denial of Service Vulnerability
BIT-dotnet-sdk-2021-1721.NET Core and Visual Studio Denial of Service Vulnerability2024-03-06vendor · osvUS
.NET Core and Visual Studio Denial of Service Vulnerability

also known as (7)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv nvd NVD CVE.org MITRE

published 2021-02-25modified 2026-06-17

references (9)

External citations — patches, advisories, analysis.

scry

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