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 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 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 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

Security improvements

An information disclosure vulnerability exists when the .NET Framework improperly handles objects in memory. An attacker who successfully exploited the vulnerability could disclose contents of an affected system's memory. To exploit the vulnerability, an authenticated attacker would need to run a specially crafted application. The update addresses the vulnerability by correcting how the .NET Framework handles objects in memory.

To learn more about the vulnerabilities, go to the following Common Vulnerabilities and Exposures (CVE).

Quality and reliability improvements

WCF1

- Addressed an issue with WCF services sometimes failing to start when starting multiple services concurrently.

Winforms

- Addressed a regression introduced in .NET Framework 4.8, where Control.AccessibleName, Control.AccessibleRole, and Control.AccessibleDescription properties stopped working for the following controls:Label, GroupBox, ToolStrip, ToolStripItems, StatusStrip, StatusStripItems, PropertyGrid, ProgressBar, ComboBox, MenuStrip, MenuItems, DataGridView.

- Addressed a regression in accessible name for combo box items for data bound combo boxes. .NET Framework 4.8 started using type name instead of the value of the DisplayMember property as an accessible name, this improvement uses the DisplayMember again.

ASP.NET

- Disabled resuse of AppPathModifier in ASP.Net control output.

- HttpCookie objects in the ASP.Net request context will be created with configured defaults for cookie flags instead of .NET-style primitive defaults to match the behavior of `new HttpCookie(name)`.

SQL

- Addressed a failure that sometimes occured when a user connects to one Azure SQL database, performed an enclave based operation, and then connected to another database under the same server that has the same Attestation URL and performed an enclave operation on the second server.

CLR2

- Added a CLR config variable Thread_AssignCpuGroups (1 by default) that can be set to 0 to disable automatic CPU group assignment done by the CLR for new threads created by Thread.Start() and thread pool threads, such that an app may do its own thread-spreading.

- Addressed a rare data corruption that can occur when using new API’s such as Unsafe.ByteOffset

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.

Symptom

Some ASP.Net applications fail during precompilation. The error message that you receive will likely contain the words “Error ASPCONFIG.”

An invalid configuration state in either the “sessionState,” “anonymouseIdentification,” or “authentication/forms” sections of “System.web” configuration. This might occur during build-and-publish routines if configuration transformations leave the Web.config file in an intermediate state for precompilation.

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.

Symptom

Some ASP.Net applications may not deliver cookieless tokens in the URI, possibly resulting in 302-redirect loops or lost or missing session state.

The ASP.Net features for Session State, Anonymous Identification, and Forms Authentication all rely on issuing tokens to a web client, and they all allow the option for those tokens to be delivered in a cookie or embedded in the URI for clients that don’t support cookies. The URI-embedding has long been an insecure and disrecommended practice and this KB quietly disables issuing tokens in URI’s unless one of these three features explicitly requests a cookie mode of “UseUri” in configuration. Configurations that specify “AutoDetect” or “UseDeviceProfile” may inadvertently result in attempted and failed embedding of these tokens in the URI.

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.

Additional information about this update

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

  • 4579977 Description of the Security and Quality Rollup for .NET Framework 3.5.1, 4.5.2, 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 (KB4579977)

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

Windows Update and Microsoft Update

Yes

None. This update will be downloaded and installed automatically from Windows Update if you are an ESU customer.

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 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.

Update replacement information

This update replaces previously released updates 4576628.

File Information

x86

File name

File version

File size

Date

Time

Aspnet_perf.dll

4.8.4332.0

36,240

23-Mar-2021

04:07

aspnet_wp.exe

4.8.4332.0

39,808

23-Mar-2021

04:07

clr.dll

4.8.4332.0

8,037,776

23-Mar-2021

04:07

clrjit.dll

4.8.4332.0

554,872

23-Mar-2021

04:07

dfdll.dll

4.8.4240.0

178,056

23-Mar-2021

04:07

mscordacwks.dll

4.8.4332.0

1,307,512

23-Mar-2021

04:07

mscordbi.dll

4.8.4332.0

1,188,728

23-Mar-2021

04:07

mscoreei.dll

4.8.4180.0

581,920

23-Mar-2021

04:07

mscorlib.dll

4.8.4332.0

5,672,328

23-Mar-2021

04:07

Placeholder.dll

4.8.4240.0

18,312

23-Mar-2021

04:07

VsVersion.dll

14.8.4240.0

11,656

23-Mar-2021

04:07

PenIMC2_v0400.dll

4.8.4240.0

99,712

23-Mar-2021

04:07

peverify.dll

4.8.4332.0

182,672

23-Mar-2021

04:07

PresentationCore.dll

4.8.4240.0

3,671,432

23-Mar-2021

04:07

PresentationFramework.dll

4.8.4240.0

6,269,832

23-Mar-2021

04:07

PresentationFramework-SystemData.dll

4.8.4240.0

17,800

23-Mar-2021

04:07

PresentationHost_v0400.dll

4.8.4240.0

233,848

23-Mar-2021

04:07

PresentationHost_v0400.dll.mui

4.8.4240.0

77,704

23-Mar-2021

04:07

PresentationNative_v0400.dll

4.8.4240.0

923,000

23-Mar-2021

04:07

ReachFramework.dll

4.8.4110.0

677,656

23-Mar-2021

04:07

ServiceMonikerSupport.dll

4.8.4332.0

24,440

23-Mar-2021

04:07

SMDiagnostics.dll

4.8.4332.0

66,320

23-Mar-2021

04:07

SOS.dll

4.8.4332.0

767,376

23-Mar-2021

04:07

System.Speech.dll

4.8.4210.0

676,736

23-Mar-2021

04:07

System.Activities.dll

4.8.4332.0

1,526,576

23-Mar-2021

04:07

System.Activities.Presentation.dll

4.8.4180.0

2,127,136

23-Mar-2021

04:07

System.Core.dll

4.8.4240.0

1,549,080

23-Mar-2021

04:07

System.IdentityModel.dll

4.8.4332.0

1,086,744

23-Mar-2021

04:07

System.IdentityModel.Services.dll

4.8.4332.0

191,368

23-Mar-2021

04:07

System.Printing.dll

4.8.4110.0

399,640

23-Mar-2021

04:07

System.Runtime.Serialization.dll

4.8.4332.0

1,047,320

23-Mar-2021

04:07

System.ServiceModel.Activities.dll

4.8.4332.0

555,400

23-Mar-2021

04:07

System.ServiceModel.Channels.dll

4.8.4332.0

150,904

23-Mar-2021

04:07

System.ServiceModel.Discovery.dll

4.8.4332.0

297,848

23-Mar-2021

04:07

System.ServiceModel.dll

4.8.4332.0

6,383,904

23-Mar-2021

04:07

System.ServiceModel.Internals.dll

4.8.4332.0

246,552

23-Mar-2021

04:07

System.ServiceModel.WasHosting.dll

4.8.4332.0

33,168

23-Mar-2021

04:07

System.ServiceModel.Web.dll

4.8.4332.0

321,816

23-Mar-2021

04:07

System.Web.ApplicationServices.dll

4.8.4332.0

63,776

23-Mar-2021

04:07

System.Web.Extensions.dll

4.8.4332.0

1,842,480

23-Mar-2021

04:07

System.Windows.Forms.DataVisualization.dll

4.8.4210.0

1,712,512

23-Mar-2021

04:07

System.Workflow.Activities.dll

4.8.4110.0

1,051,112

23-Mar-2021

04:07

System.Workflow.ComponentModel.dll

4.8.4110.0

1,557,272

23-Mar-2021

04:07

System.Workflow.Runtime.dll

4.8.4110.0

503,064

23-Mar-2021

04:07

System.Configuration.dll

4.8.4190.0

421,536

23-Mar-2021

04:07

System.Data.dll

4.8.4332.0

3,476,360

23-Mar-2021

04:07

System.Deployment.dll

4.8.4240.0

1,595,136

23-Mar-2021

04:07

System.dll

4.8.4210.0

3,552,520

23-Mar-2021

04:07

System.Drawing.Design.dll

4.8.4210.0

125,192

23-Mar-2021

04:07

System.Security.dll

4.8.4332.0

320,304

23-Mar-2021

04:07

System.Web.dll

4.8.4332.0

5,410,184

23-Mar-2021

04:07

System.Windows.Controls.Ribbon.dll

4.8.4240.0

743,816

23-Mar-2021

04:07

System.Windows.Forms.dll

4.8.4332.0

5,914,912

23-Mar-2021

04:07

System.Xaml.dll

4.8.4240.0

632,088

23-Mar-2021

04:07

UIAutomationClient.dll

4.8.4240.0

170,888

23-Mar-2021

04:07

UIAutomationClientsideProviders.dll

4.8.4240.0

354,184

23-Mar-2021

04:07

UIAutomationProvider.dll

4.8.4240.0

41,864

23-Mar-2021

04:07

UIAutomationTypes.dll

4.8.4240.0

215,944

23-Mar-2021

04:07

webengine.dll

4.8.4332.0

19,320

23-Mar-2021

04:07

webengine4.dll

4.8.4332.0

564,624

23-Mar-2021

04:07

WindowsBase.dll

4.8.4240.0

1,298,816

23-Mar-2021

04:07

WindowsFormsIntegration.dll

4.8.4180.0

105,248

23-Mar-2021

04:07

WorkflowServiceHostPerformanceCounters.dll

4.8.4110.0

89,368

23-Mar-2021

04:07

WPFFontCache_v0400.exe.mui

4.8.4240.0

12,160

23-Mar-2021

04:07

WPFFontCache_v0400.exe

4.8.4240.0

19,872

23-Mar-2021

04:07

wpfgfx_v0400.dll

4.8.4240.0

1,618,824

23-Mar-2021

04:07

x64

File name

File version

File size

Date

Time

UIAutomationClient.dll

4.8.4240.0

170,888

23-Mar-2021

04:07

UIAutomationClientsideProviders.dll

4.8.4240.0

354,184

23-Mar-2021

04:07

UIAutomationProvider.dll

4.8.4240.0

41,864

23-Mar-2021

04:07

UIAutomationTypes.dll

4.8.4240.0

215,944

23-Mar-2021

04:07

webengine.dll

4.8.4332.0

21,392

23-Mar-2021

04:37

webengine.dll

4.8.4332.0

19,320

23-Mar-2021

04:07

webengine4.dll

4.8.4332.0

675,216

23-Mar-2021

04:37

webengine4.dll

4.8.4332.0

564,624

23-Mar-2021

04:07

WindowsBase.dll

4.8.4240.0

1,298,816

23-Mar-2021

04:07

WindowsFormsIntegration.dll

4.8.4180.0

105,248

23-Mar-2021

04:07

WorkflowServiceHostPerformanceCounters.dll

4.8.4110.0

102,672

23-Mar-2021

04:07

WorkflowServiceHostPerformanceCounters.dll

4.8.4110.0

89,368

23-Mar-2021

04:07

WPFFontCache_v0400.exe.mui

4.8.4240.0

12,168

23-Mar-2021

04:07

WPFFontCache_v0400.exe.mui

4.8.4240.0

12,160

23-Mar-2021

04:07

WPFFontCache_v0400.exe

4.8.4240.0

21,920

23-Mar-2021

04:07

WPFFontCache_v0400.exe

4.8.4240.0

19,872

23-Mar-2021

04:07

wpfgfx_v0400.dll

4.8.4240.0

2,050,440

23-Mar-2021

04:07

wpfgfx_v0400.dll

4.8.4240.0

1,618,824

23-Mar-2021

04:07

Aspnet_perf.dll

4.8.4332.0

41,848

23-Mar-2021

04:37

Aspnet_perf.dll

4.8.4332.0

36,240

23-Mar-2021

04:07

aspnet_wp.exe

4.8.4332.0

45,464

23-Mar-2021

04:37

aspnet_wp.exe

4.8.4332.0

39,808

23-Mar-2021

04:07

clr.dll

4.8.4332.0

11,246,968

23-Mar-2021

04:37

clr.dll

4.8.4332.0

8,037,776

23-Mar-2021

04:07

clrjit.dll

4.8.4332.0

1,358,224

23-Mar-2021

04:37

clrjit.dll

4.8.4332.0

554,872

23-Mar-2021

04:07

compatjit.dll

4.8.4332.0

1,272,712

23-Mar-2021

04:37

dfdll.dll

4.8.4240.0

214,912

23-Mar-2021

04:07

dfdll.dll

4.8.4240.0

178,056

23-Mar-2021

04:07

mscordacwks.dll

4.8.4332.0

1,801,096

23-Mar-2021

04:37

mscordacwks.dll

4.8.4332.0

1,307,512

23-Mar-2021

04:07

mscordbi.dll

4.8.4332.0

1,655,176

23-Mar-2021

04:37

mscordbi.dll

4.8.4332.0

1,188,728

23-Mar-2021

04:07

mscoreei.dll

4.8.4180.0

689,952

23-Mar-2021

04:07

mscoreei.dll

4.8.4180.0

581,920

23-Mar-2021

04:07

mscorlib.dll

4.8.4332.0

5,431,696

23-Mar-2021

04:37

mscorlib.dll

4.8.4332.0

5,672,328

23-Mar-2021

04:07

VsVersion.dll

14.8.4240.0

11,656

23-Mar-2021

04:07

Placeholder.dll

4.8.4240.0

20,352

23-Mar-2021

04:07

Placeholder.dll

4.8.4240.0

18,312

23-Mar-2021

04:07

VsVersion.dll

14.8.4240.0

11,656

23-Mar-2021

04:07

PenIMC2_v0400.dll

4.8.4240.0

120,712

23-Mar-2021

04:07

PenIMC2_v0400.dll

4.8.4240.0

99,712

23-Mar-2021

04:07

peverify.dll

4.8.4332.0

265,608

23-Mar-2021

04:37

peverify.dll

4.8.4332.0

182,672

23-Mar-2021

04:07

PresentationCore.dll

4.8.4240.0

3,648,384

23-Mar-2021

04:07

PresentationCore.dll

4.8.4240.0

3,671,432

23-Mar-2021

04:07

PresentationFramework.dll

4.8.4240.0

6,269,832

23-Mar-2021

04:07

PresentationFramework-SystemData.dll

4.8.4240.0

17,800

23-Mar-2021

04:07

PresentationHost_v0400.dll

4.8.4240.0

302,464

23-Mar-2021

04:07

PresentationHost_v0400.dll.mui

4.8.4240.0

77,696

23-Mar-2021

04:07

PresentationHost_v0400.dll

4.8.4240.0

233,848

23-Mar-2021

04:07

PresentationHost_v0400.dll.mui

4.8.4240.0

77,704

23-Mar-2021

04:07

PresentationNative_v0400.dll

4.8.4240.0

1,164,168

23-Mar-2021

04:07

PresentationNative_v0400.dll

4.8.4240.0

923,000

23-Mar-2021

04:07

ReachFramework.dll

4.8.4110.0

677,656

23-Mar-2021

04:07

ServiceMonikerSupport.dll

4.8.4332.0

27,512

23-Mar-2021

04:37

ServiceMonikerSupport.dll

4.8.4332.0

24,440

23-Mar-2021

04:07

SMDiagnostics.dll

4.8.4332.0

66,320

23-Mar-2021

04:07

SOS.dll

4.8.4332.0

921,488

23-Mar-2021

04:37

SOS.dll

4.8.4332.0

767,376

23-Mar-2021

04:07

System.Speech.dll

4.8.4210.0

676,736

23-Mar-2021

04:07

System.Activities.dll

4.8.4332.0

1,526,576

23-Mar-2021

04:07

System.Activities.Presentation.dll

4.8.4180.0

2,127,136

23-Mar-2021

04:07

System.Core.dll

4.8.4240.0

1,549,080

23-Mar-2021

04:07

System.IdentityModel.dll

4.8.4332.0

1,086,744

23-Mar-2021

04:07

System.IdentityModel.Services.dll

4.8.4332.0

191,368

23-Mar-2021

04:07

System.Printing.dll

4.8.4110.0

400,152

23-Mar-2021

04:07

System.Printing.dll

4.8.4110.0

399,640

23-Mar-2021

04:07

System.Runtime.Serialization.dll

4.8.4332.0

1,047,320

23-Mar-2021

04:07

System.ServiceModel.Activities.dll

4.8.4332.0

555,400

23-Mar-2021

04:07

System.ServiceModel.Channels.dll

4.8.4332.0

150,904

23-Mar-2021

04:07

System.ServiceModel.Discovery.dll

4.8.4332.0

297,848

23-Mar-2021

04:07

System.ServiceModel.dll

4.8.4332.0

6,383,904

23-Mar-2021

04:07

System.ServiceModel.Internals.dll

4.8.4332.0

246,552

23-Mar-2021

04:07

System.ServiceModel.WasHosting.dll

4.8.4332.0

33,168

23-Mar-2021

04:07

System.ServiceModel.Web.dll

4.8.4332.0

321,816

23-Mar-2021

04:07

System.Web.ApplicationServices.dll

4.8.4332.0

63,776

23-Mar-2021

04:07

System.Web.Extensions.dll

4.8.4332.0

1,842,480

23-Mar-2021

04:07

System.Windows.Forms.DataVisualization.dll

4.8.4210.0

1,712,512

23-Mar-2021

04:07

System.Workflow.Activities.dll

4.8.4110.0

1,051,112

23-Mar-2021

04:07

System.Workflow.ComponentModel.dll

4.8.4110.0

1,557,272

23-Mar-2021

04:07

System.Workflow.Runtime.dll

4.8.4110.0

503,064

23-Mar-2021

04:07

System.configuration.dll

4.8.4190.0

421,536

23-Mar-2021

04:07

System.Data.dll

4.8.4332.0

3,543,440

23-Mar-2021

04:37

System.Data.dll

4.8.4332.0

3,476,360

23-Mar-2021

04:07

System.Deployment.dll

4.8.4240.0

1,595,136

23-Mar-2021

04:07

System.dll

4.8.4210.0

3,552,520

23-Mar-2021

04:07

System.Drawing.Design.dll

4.8.4210.0

125,192

23-Mar-2021

04:07

System.Security.dll

4.8.4332.0

320,304

23-Mar-2021

04:07

System.Web.dll

4.8.4332.0

5,397,880

23-Mar-2021

04:37

System.Web.dll

4.8.4332.0

5,410,184

23-Mar-2021

04:07

System.Windows.Controls.Ribbon.dll

4.8.4240.0

743,816

23-Mar-2021

04:07

System.Windows.Forms.dll

4.8.4332.0

5,914,912

23-Mar-2021

04:07

System.Xaml.dll

4.8.4240.0

632,088

23-Mar-2021

04:07

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