Notice

Revised 6/8/2021

On June 8th, 2021, this update was released to replace a previous update to address a “revocation server was offline” error that may occur during installation. If you've already installed a previous release of this update, no action is required. To obtain the latest version of these updates, see the "How to obtain and install the update" section of the individual update article.  Links to each article are found in the "Additional information about this update" section of this article.

On March 9th, 2021, this update was released to replace a previous update to address a "A required certificate is not within its validity period" error that may occur during installation.

Applies to:

Microsoft .NET Framework 3.5.1 Microsoft .NET Framework 4.5.2 Microsoft .NET Framework 4.6 Microsoft .NET Framework 4.6.1 Microsoft .NET Framework 4.6.2 Microsoft .NET Framework 4.7 Microsoft .NET Framework 4.7.1 Microsoft .NET Framework 4.7.2 Microsoft .NET Framework 4.8

IMPORTANT Verify that you have installed the required updates listed in the How to get this update section before installing this update. 

IMPORTANT Some customers who use Windows Server 2008 R2 SP1 and have activated their ESU multiple activation key (MAK) add-on before installing the January 14, 2020 updates might need to re-activate their key. Re-activation on the affected devices should only be required once.  For information on activation, see this blog post.

IMPORTANT WSUS scan cab files will continue to be available for Windows 7 SP1 and Windows Server 2008 R2 SP1. If you have a subset of devices running these operating systems without ESU, they might show as non-compliant in your patch management and compliance toolsets.

IMPORTANT Customers who have purchased the Extended Security Update (ESU) for on-premises versions of these operating systems must follow the procedures in KB4522133 to continue receiving security updates after extended support ends on January 14, 2020. For more information on ESU and which editions are supported, see KB4497181.

IMPORTANT Starting on January 15, 2020, a full-screen notification will appear that describes the risk of continuing to use Windows 7 Service Pack 1 after it reaches end of support on January 14, 2020. The notification will remain on the screen until you interact with it. This notification will only appear on the following editions of Windows 7 Service Pack 1:

Note The notification will not appear on domain-joined machines or machines in kiosk mode.

IMPORTANT Starting in August, 2019, updates to .NET Framework 4.6 and above, for Windows Server 2008 SP1, Windows Server 2008 R2 SP1, and Windows 7SP1, require SHA-2 Code signing support. Please make sure that you have all the latest Windows Updates before applying this update to avoid installation issues. For more detailed information about SHA-2 code signing support updates, please see KB 4474419.

IMPORTANT All updates for .NET Framework 4.7.2, 4.7.1, 4.7, 4.6.2, 4.6.1, and 4.6 require that the d3dcompiler_47.dll update is installed. We recommend that you install the included d3dcompiler_47.dll update before you apply this update. For more information about the d3dcompiler_47.dll, see KB 4019990.

IMPORTANT If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

Important

This update is included in the Security and Quality Rollup that's dated February 9, 2021. Parts of this update were previously released in the rollup that's dated October 13, 2020.

Summary

Security Improvements

This security update addresses a denial of service vulnerability in .NET Framework. For more information please see CVE-2021-24111.

Quality Improvements

For a list of improvements that were released with this update, please see the article links in the Additional Information section of this article.

Known issues in some parts of this update

Symptom

This update does not install, and it returns either or both of the following error messages:

  • -2146762495

  • A required certificate is not within its validity period when verifying against the current system clock or the timestamp in the signed file.

  • The revocation function was unable to check revocation because the revocation server was offline.

Workaround

This issue was corrected by the latest release of the affected parts in this update.

If you've already installed a previous release of the affected parts, no action is required.

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

  • 4578952 Description of the Security and Quality Rollup for .NET Framework 3.5.1 for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB4578952)

  • 4578955 Description of the Security and Quality Rollup for .NET Framework 4.5.2 for Windows 7 SP1 and Windows Server 2008 R2 SP1 and Windows Server 2008 SP2 (KB4578955)

  • 4600945 Description of the Security and Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows 7 SP1 and Windows Server 2008 R2 SP1 and Windows Server 2008 SP2 (KB4600945)

  • 4600944 Description of the Security and Quality Rollup for .NET Framework 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB4600944)

Release Channel

Available

Next Step

Windows Update and Microsoft Update

Yes

None. This update will be downloaded and installed automatically from Windows Update.

Microsoft Update Catalog

Yes

To get the standalone package for this update, go to the Microsoft Update Catalog website.

Windows Server Update Services (WSUS)

Yes

This update will automatically sync with WSUS if you configure Products and Classifications as follows:

Product: Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1,Windows Embedded Standard 7 Service Pack 1, Windows Embedded POSReady 7

Classification: Security Updates

Information about protection and security

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