Applies To.NET

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. Follow the instructions under How to obtain and install the update to get the updated version.

On April 13th, 2021, this update was released to replace a previous release of this update.

Applies to:

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.

Summary

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

Known issues in 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 this update.  Follow the instructions under How to obtain and install the update to get the updated version.

If you've already installed a previous release of this update, 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.

  • 4602958 Description of the Security Only Update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB4602958)

How to obtain and install the update

Before installing this update

Prerequisite:

To apply this update, you must have .NET Framework 4.8 installed.

You must install the updates listed below and restart your device before installing the latest Rollup. Installing these updates improves the reliability of the update process and mitigates potential issues while installing the Rollup and applying Microsoft security fixes.

  1. The March 12, 2019 servicing stack update (SSU) (KB4490628). To get the standalone package for this SSU, search for it in the Microsoft Update Catalog. This update is required to install updates that are only SHA-2 signed.

  2. The latest SHA-2 update (KB4474419) released September 10, 2019. If you are using Windows Update, the latest SHA-2 update will be offered to you automatically. This update is required to install updates that are only SHA-2 signed. For more information on SHA-2 updates, see 2019 SHA-2 Code Signing Support requirement for Windows and WSUS.

  3. The Extended Security Updates (ESU) Licensing Preparation Package (KB4538483) released February 11, 2020. The ESU licensing preparation package will be offered to you from WSUS. To get the standalone package for ESU licensing preparation package, search for it in the Microsoft Update Catalog.

Install this update

Release Channel

Available

Next Step

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

Restart requirement

You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.

Update deployment information

For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:

20210209 Security update deployment information: February 9, 2021

Update removal information

Note We do not recommend that you remove any security update. To remove this update, use the Programs and Features item in Control Panel.

Update restart information

This update does not require a system restart after you apply it unless files that are being updated are locked or are being used.

File Information

x86

File name

File version

File size

Date

Time

Aspnet_perf.dll

4.8.4330.0

36,232

05-Jan-2021

21:19

aspnet_wp.exe

4.8.4330.0

39,824

05-Jan-2021

21:19

System.Web.ApplicationServices.dll

4.8.4330.0

63,768

05-Jan-2021

20:59

System.Web.Extensions.dll

4.8.4330.0

1,842,448

05-Jan-2021

20:59

System.Web.dll

4.8.4330.0

5,410,184

05-Jan-2021

21:19

webengine.dll

4.8.4330.0

19,328

05-Jan-2021

21:19

webengine4.dll

4.8.4330.0

564,616

05-Jan-2021

21:19

x64

File name

File version

File size

Date

Time

Aspnet_perf.dll

4.8.4330.0

41,864

05-Jan-2021

20:59

Aspnet_perf.dll

4.8.4330.0

36,232

05-Jan-2021

21:19

aspnet_wp.exe

4.8.4330.0

45,456

05-Jan-2021

20:59

aspnet_wp.exe

4.8.4330.0

39,824

05-Jan-2021

21:19

System.Web.ApplicationServices.dll

4.8.4330.0

63,768

05-Jan-2021

20:59

System.Web.Extensions.dll

4.8.4330.0

1,842,448

05-Jan-2021

20:59

System.Web.dll

4.8.4330.0

5,397,896

05-Jan-2021

20:59

System.Web.dll

4.8.4330.0

5,410,184

05-Jan-2021

21:19

webengine.dll

4.8.4330.0

21,376

05-Jan-2021

20:59

webengine.dll

4.8.4330.0

19,328

05-Jan-2021

21:19

webengine4.dll

4.8.4330.0

675,208

05-Jan-2021

20:59

webengine4.dll

4.8.4330.0

564,616

05-Jan-2021

21:19

Information about protection and security

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