Applies To.NET

Notice

Revised 2/2/2022

On February 2nd, 2022, guidance was added to this article regarding how to install security-only updates after some changes were made to the ESU program. See the Known Issues section of this article for details.

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.

On July 23, 2020, update KB4552953 v2 was released to replace v1 for .NET Framework 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1. The v1 update did not install for customers who had certain ESU configurations.  The v2 update corrects the issue for customers who could not install the v1 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 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

A remote code execution vulnerability exists in .NET Framework software when the software fails to check the source markup of a file. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of .NET Framework. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. The security update addresses the vulnerability by correcting how .NET Framework checks the source markup of a file.

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

A denial of service vulnerability exists when .NET Framework improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against a .NET Framework web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the .NET Framework application. The update addresses the vulnerability by correcting how the .NET Framework web application handles web requests.

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

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 changes rolled out to the Azure Instance Metadata Service (IMDS) attested data to switch from the Baltimore CyberTrust CA Root to the DigiCert Global G2 CA Root. You can find detailed information about this change here: Azure Instance Metadata Service-Attested data TLS: Critical changes are almost here! - Microsoft Tech Community. This update does not install and may return error message:

“Fatal error during installation” with error code: 0x80070643 (or 0x643).

Workaround

This issue was addressed by the updates released in January 2022, see KB5008885 for update details. To install any previously released update, you will need to apply the latest January 2022 .NET Framework security-only update to your system before applying a previous security-only update. If you've already installed a previously released 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.

  • 4556403 Description of the Security Only Update 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 (KB4556403)

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:

20200512 Security update deployment information: May 12, 2020

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

The English (United States) version of this software update installs files that have the attributes that are listed in the following tables.

x86

File name

File version

File size

Date

Time

clr.dll

4.8.4180.0

8,044,832

09-Apr-2020

18:04

clrjit.dll

4.8.4180.0

561,648

09-Apr-2020

18:04

mscordacwks.dll

4.8.4180.0

1,315,104

09-Apr-2020

18:04

mscordbi.dll

4.8.4180.0

1,196,320

09-Apr-2020

18:04

mscoreei.dll

4.8.4180.0

581,920

09-Apr-2020

18:04

mscorlib.dll

4.8.4180.0

5,678,576

09-Apr-2020

18:04

Placeholder.dll

4.8.4180.0

26,096

09-Apr-2020

18:04

VsVersion.dll

14.8.4180.0

19,232

09-Apr-2020

18:04

PenIMC2_v0400.dll

4.8.4180.0

107,504

09-Apr-2020

18:04

peverify.dll

4.8.4180.0

190,232

09-Apr-2020

18:04

PresentationCore.dll

4.8.4180.0

3,676,440

09-Apr-2020

18:04

PresentationFramework.dll

4.8.4180.0

6,271,264

09-Apr-2020

17:54

PresentationFramework-SystemData.dll

4.8.4180.0

25,376

09-Apr-2020

17:54

PresentationHost_v0400.dll

4.8.4180.0

241,648

09-Apr-2020

18:04

PresentationHost_v0400.dll.mui

4.8.4180.0

85,272

09-Apr-2020

18:04

PresentationNative_v0400.dll

4.8.4180.0

930,808

09-Apr-2020

18:04

ServiceMonikerSupport.dll

4.8.4180.0

32,272

09-Apr-2020

18:04

SMDiagnostics.dll

4.8.4180.0

73,880

09-Apr-2020

17:54

SOS.dll

4.8.4180.0

774,944

09-Apr-2020

18:04

System.Activities.dll

4.8.4180.0

1,534,312

09-Apr-2020

17:54

System.Core.dll

4.8.4180.0

1,556,832

09-Apr-2020

17:54

System.IdentityModel.dll

4.8.4180.0

1,094,504

09-Apr-2020

17:54

System.IdentityModel.Services.dll

4.8.4180.0

199,152

09-Apr-2020

17:54

System.Runtime.Serialization.dll

4.8.4180.0

1,054,872

09-Apr-2020

17:54

System.ServiceModel.Channels.dll

4.8.4180.0

158,704

09-Apr-2020

17:54

System.ServiceModel.Discovery.dll

4.8.4180.0

309,024

09-Apr-2020

17:54

System.ServiceModel.dll

4.8.4180.0

6,389,336

09-Apr-2020

17:54

System.ServiceModel.Internals.dll

4.8.4180.0

254,096

09-Apr-2020

17:54

System.ServiceModel.WasHosting.dll

4.8.4180.0

40,736

09-Apr-2020

17:54

System.Windows.Controls.Ribbon.dll

4.8.4180.0

751,392

09-Apr-2020

17:54

System.Xaml.dll

4.8.4180.0

640,056

09-Apr-2020

17:54

UIAutomationClient.dll

4.8.4180.0

178,464

09-Apr-2020

17:54

UIAutomationClientsideProviders.dll

4.8.4180.0

361,760

09-Apr-2020

17:54

UIAutomationProvider.dll

4.8.4180.0

49,648

09-Apr-2020

17:54

UIAutomationTypes.dll

4.8.4180.0

223,512

09-Apr-2020

17:54

WindowsBase.dll

4.8.4180.0

1,306,392

09-Apr-2020

17:54

WPFFontCache_v0400.exe.mui

4.8.4180.0

19,744

09-Apr-2020

18:04

WPFFontCache_v0400.exe

4.8.4180.0

27,472

09-Apr-2020

18:04

wpfgfx_v0400.dll

4.8.4180.0

1,626,608

09-Apr-2020

18:04

x64

File name

File version

File size

Date

Time

clr.dll

4.8.4180.0

11,251,192

09-Apr-2020

17:54

clr.dll

4.8.4180.0

8,044,832

09-Apr-2020

18:04

clrjit.dll

4.8.4180.0

1,365,272

09-Apr-2020

17:54

clrjit.dll

4.8.4180.0

561,648

09-Apr-2020

18:04

compatjit.dll

4.8.4180.0

1,280,800

09-Apr-2020

17:54

mscordacwks.dll

4.8.4180.0

1,808,672

09-Apr-2020

17:54

mscordacwks.dll

4.8.4180.0

1,315,104

09-Apr-2020

18:04

mscordbi.dll

4.8.4180.0

1,662,752

09-Apr-2020

17:54

mscordbi.dll

4.8.4180.0

1,196,320

09-Apr-2020

18:04

mscoreei.dll

4.8.4180.0

689,952

09-Apr-2020

17:54

mscoreei.dll

4.8.4180.0

581,920

09-Apr-2020

18:04

mscorlib.dll

4.8.4180.0

5,439,264

09-Apr-2020

17:54

mscorlib.dll

4.8.4180.0

5,678,576

09-Apr-2020

18:04

VsVersion.dll

14.8.4180.0

19,232

09-Apr-2020

17:54

Placeholder.dll

4.8.4180.0

27,936

09-Apr-2020

17:54

Placeholder.dll

4.8.4180.0

26,096

09-Apr-2020

18:04

VsVersion.dll

14.8.4180.0

19,232

09-Apr-2020

18:04

PenIMC2_v0400.dll

4.8.4180.0

128,288

09-Apr-2020

17:54

PenIMC2_v0400.dll

4.8.4180.0

107,504

09-Apr-2020

18:04

peverify.dll

4.8.4180.0

273,184

09-Apr-2020

17:54

peverify.dll

4.8.4180.0

190,232

09-Apr-2020

18:04

PresentationCore.dll

4.8.4180.0

3,652,384

09-Apr-2020

17:54

PresentationCore.dll

4.8.4180.0

3,676,440

09-Apr-2020

18:04

PresentationFramework.dll

4.8.4180.0

6,271,264

09-Apr-2020

17:54

PresentationFramework-SystemData.dll

4.8.4180.0

25,376

09-Apr-2020

17:54

PresentationHost_v0400.dll

4.8.4180.0

310,048

09-Apr-2020

17:54

PresentationHost_v0400.dll.mui

4.8.4180.0

85,280

09-Apr-2020

17:54

PresentationHost_v0400.dll

4.8.4180.0

241,648

09-Apr-2020

18:04

PresentationHost_v0400.dll.mui

4.8.4180.0

85,272

09-Apr-2020

18:04

PresentationNative_v0400.dll

4.8.4180.0

1,171,744

09-Apr-2020

17:54

PresentationNative_v0400.dll

4.8.4180.0

930,808

09-Apr-2020

18:04

ServiceMonikerSupport.dll

4.8.4180.0

35,104

09-Apr-2020

17:54

ServiceMonikerSupport.dll

4.8.4180.0

32,272

09-Apr-2020

18:04

SMDiagnostics.dll

4.8.4180.0

73,880

09-Apr-2020

17:54

SOS.dll

4.8.4180.0

929,056

09-Apr-2020

17:54

SOS.dll

4.8.4180.0

774,944

09-Apr-2020

18:04

System.Activities.dll

4.8.4180.0

1,534,312

09-Apr-2020

17:54

System.Core.dll

4.8.4180.0

1,556,832

09-Apr-2020

17:54

System.IdentityModel.dll

4.8.4180.0

1,094,504

09-Apr-2020

17:54

System.IdentityModel.Services.dll

4.8.4180.0

199,152

09-Apr-2020

17:54

System.Runtime.Serialization.dll

4.8.4180.0

1,054,872

09-Apr-2020

17:54

System.ServiceModel.Channels.dll

4.8.4180.0

158,704

09-Apr-2020

17:54

System.ServiceModel.Discovery.dll

4.8.4180.0

309,024

09-Apr-2020

17:54

System.ServiceModel.dll

4.8.4180.0

6,389,336

09-Apr-2020

17:54

System.ServiceModel.Internals.dll

4.8.4180.0

254,096

09-Apr-2020

17:54

System.ServiceModel.WasHosting.dll

4.8.4180.0

40,736

09-Apr-2020

17:54

System.Windows.Controls.Ribbon.dll

4.8.4180.0

751,392

09-Apr-2020

17:54

System.Xaml.dll

4.8.4180.0

640,056

09-Apr-2020

17:54

UIAutomationClient.dll

4.8.4180.0

178,464

09-Apr-2020

17:54

UIAutomationClientsideProviders.dll

4.8.4180.0

361,760

09-Apr-2020

17:54

UIAutomationProvider.dll

4.8.4180.0

49,648

09-Apr-2020

17:54

UIAutomationTypes.dll

4.8.4180.0

223,512

09-Apr-2020

17:54

WindowsBase.dll

4.8.4180.0

1,306,392

09-Apr-2020

17:54

WPFFontCache_v0400.exe.mui

4.8.4180.0

19,744

09-Apr-2020

18:13

WPFFontCache_v0400.exe.mui

4.8.4180.0

19,744

09-Apr-2020

18:04

WPFFontCache_v0400.exe

4.8.4180.0

29,520

09-Apr-2020

18:13

WPFFontCache_v0400.exe

4.8.4180.0

27,472

09-Apr-2020

18:04

wpfgfx_v0400.dll

4.8.4180.0

2,058,016

09-Apr-2020

17:54

wpfgfx_v0400.dll

4.8.4180.0

1,626,608

09-Apr-2020

18:04

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