CVE-2021-26423: .NET Core and Visual Studio Denial of Service Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

Category

Denial of Service

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2021-Aug

Released

2021-08-10

Last Updated

2021-08-19

EPSS Score

3.37% (percentile: 87.4%)

Affected Products (11)

Other

• 11600
• 11720
• 11785
• 11872
• 11900
• 11901
• 11565
• 11730
• 11761
• 11864
• 11865

Security Updates (10)

• Release Notes
• Release Notes
• Release Notes
• Release Notes
• Release Notes
• Release Notes
• Release Notes
• Release Notes
• Release Notes
• Release Notes

Acknowledgments

<a href="https://twitter.com/ulldma">Peter Stöckli</a> with <a href="https://www.ergon.ch">Ergon Informatik</a>, <a href="https://twitter.com/ulldma">Peter Stöckli</a> with <a href="https://www.ergon.ch">Ergon Informatik</a>

Revision History

• 2021-08-10: Information published.
• 2021-08-10: In the Security Updates table, added links to the Release Notes. This is an informational change only.
• 2021-08-12: Revised the Security Updates table to include PowerShell 7.0 and PowerShell 7.1 because these versions of PowerShell 7 incorporate the versions of .NET Core that are affected by this vulnerability. See https://github.com/PowerShell/Announcements/issues/25 for more information.
• 2021-08-19: To comprehensively address this vulnerability, Microsoft has released .NET Core 2.1 Build Number 2.1.30. Customers who have downloaded Build 2.1.29 should download and install Build 2.1.30 to be fully protected from this vulnerability.