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.

On July 23, 2020, update KB4552952 v2 was released to replace v1 for .NET Framework 4.5.2 for Windows 7 SP1 and Windows Server 2008 R2 SP1 and Windows Server 2008 SP2. 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 4.5.2

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.

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.

Additional information about this update

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

  • 4556406 Description of the Security Only Update for .NET Framework 2.0, 3.0, 4.5.2, 4.6 for Windows Server 2008 SP2 (KB4556406)

  • 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 4.5.2 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

4.0.30319.36627

6,941,472

10-Apr-2020

00:06

clrjit.dll

4.0.30319.36627

509,728

10-Apr-2020

00:06

mscordacwks.dll

4.0.30319.36627

1,285,104

10-Apr-2020

00:06

mscordbi.dll

4.0.30319.36627

1,108,464

10-Apr-2020

00:06

mscorlib.dll

4.0.30319.36627

5,268,768

10-Apr-2020

00:06

PenIMC.dll

4.0.30319.36627

82,440

10-Apr-2020

00:06

peverify.dll

4.0.30319.36627

164,640

10-Apr-2020

00:06

PresentationCore.dll

4.0.30319.36627

3,227,632

10-Apr-2020

00:06

PresentationFramework.dll

4.0.30319.36627

6,228,256

10-Apr-2020

00:06

PresentationHost_v0400.dll

4.0.30319.36627

186,864

10-Apr-2020

00:06

PresentationHost_v0400.dll.mui

4.0.30319.36627

85,488

10-Apr-2020

00:06

PresentationNative_v0400.dll

4.0.30319.36627

790,816

10-Apr-2020

00:06

ServiceMonikerSupport.dll

4.0.30319.36627

28,960

10-Apr-2020

00:06

SMDiagnostics.dll

4.0.30319.36627

73,864

10-Apr-2020

00:06

SOS.dll

4.0.30319.36627

763,168

10-Apr-2020

00:06

System.Activities.dll

4.0.30319.36627

1,583,248

10-Apr-2020

00:06

System.Core.dll

4.0.30319.36627

1,272,464

10-Apr-2020

00:06

System.IdentityModel.dll

4.0.30319.36627

1,097,872

10-Apr-2020

00:06

System.IdentityModel.Services.dll

4.0.30319.36627

200,480

10-Apr-2020

00:06

System.Runtime.Serialization.dll

4.0.30319.36627

1,060,496

10-Apr-2020

00:06

System.ServiceModel.Channels.dll

4.0.30319.36627

160,024

10-Apr-2020

00:06

System.ServiceModel.Discovery.dll

4.0.30319.36627

313,120

10-Apr-2020

00:06

System.ServiceModel.dll

4.0.30319.36627

6,388,328

10-Apr-2020

00:06

System.ServiceModel.Internals.dll

4.0.30319.36627

255,120

10-Apr-2020

00:06

System.ServiceModel.WasHosting.dll

4.0.30319.36627

40,432

10-Apr-2020

00:06

System.Windows.Controls.Ribbon.dll

4.0.30319.36627

751,904

10-Apr-2020

00:06

System.Xaml.dll

4.0.30319.36627

641,408

10-Apr-2020

00:06

WindowsBase.dll

4.0.30319.36627

1,242,392

10-Apr-2020

00:06

WPFFontCache_v0400.exe.mui

4.0.30319.36627

19,952

10-Apr-2020

00:06

WPFFontCache_v0400.exe

4.0.30319.36627

25,424

10-Apr-2020

00:06

wpfgfx_v0400.dll

4.0.30319.36627

1,649,136

10-Apr-2020

00:06

VsVersion.dll

12.0.52415.36415

18,088

10-Apr-2020

00:02

msvcp120_clr0400.dll

12.0.52480.36480

536,856

10-Apr-2020

00:02

msvcr120_clr0400.dll

12.0.52480.36480

875,800

10-Apr-2020

00:02

x64

File name

File version

File size

Date

Time

clr.dll

4.0.30319.36627

10,071,328

10-Apr-2020

00:29

clr.dll

4.0.30319.36627

6,941,472

10-Apr-2020

00:06

clrjit.dll

4.0.30319.36627

1,235,232

10-Apr-2020

00:29

clrjit.dll

4.0.30319.36627

509,728

10-Apr-2020

00:06

mscordacwks.dll

4.0.30319.36627

1,731,872

10-Apr-2020

00:29

mscordacwks.dll

4.0.30319.36627

1,285,104

10-Apr-2020

00:06

mscordbi.dll

4.0.30319.36627

1,534,240

10-Apr-2020

00:29

mscordbi.dll

4.0.30319.36627

1,108,464

10-Apr-2020

00:06

mscorlib.dll

4.0.30319.36627

5,222,688

10-Apr-2020

00:29

mscorlib.dll

4.0.30319.36627

5,268,768

10-Apr-2020

00:06

PenIMC.dll

4.0.30319.36627

95,736

10-Apr-2020

00:29

PenIMC.dll

4.0.30319.36627

82,440

10-Apr-2020

00:06

peverify.dll

4.0.30319.36627

226,592

10-Apr-2020

00:29

peverify.dll

4.0.30319.36627

164,640

10-Apr-2020

00:06

PresentationCore.dll

4.0.30319.36627

3,211,552

10-Apr-2020

00:29

PresentationCore.dll

4.0.30319.36627

3,227,632

10-Apr-2020

00:06

PresentationFramework.dll

4.0.30319.36627

6,228,256

10-Apr-2020

00:06

PresentationHost_v0400.dll

4.0.30319.36627

232,944

10-Apr-2020

00:29

PresentationHost_v0400.dll.mui

4.0.30319.36627

85,496

10-Apr-2020

00:29

PresentationHost_v0400.dll

4.0.30319.36627

186,864

10-Apr-2020

00:06

PresentationHost_v0400.dll.mui

4.0.30319.36627

85,488

10-Apr-2020

00:06

PresentationNative_v0400.dll

4.0.30319.36627

1,078,768

10-Apr-2020

00:29

PresentationNative_v0400.dll

4.0.30319.36627

790,816

10-Apr-2020

00:06

ServiceMonikerSupport.dll

4.0.30319.36627

29,472

10-Apr-2020

00:29

ServiceMonikerSupport.dll

4.0.30319.36627

28,960

10-Apr-2020

00:06

SMDiagnostics.dll

4.0.30319.36627

73,864

10-Apr-2020

00:06

SOS.dll

4.0.30319.36627

823,792

10-Apr-2020

00:29

SOS.dll

4.0.30319.36627

763,168

10-Apr-2020

00:06

System.Activities.dll

4.0.30319.36627

1,583,248

10-Apr-2020

00:06

System.Core.dll

4.0.30319.36627

1,272,464

10-Apr-2020

00:06

System.IdentityModel.dll

4.0.30319.36627

1,097,872

10-Apr-2020

00:06

System.IdentityModel.Services.dll

4.0.30319.36627

200,480

10-Apr-2020

00:06

System.Runtime.Serialization.dll

4.0.30319.36627

1,060,496

10-Apr-2020

00:06

System.ServiceModel.Channels.dll

4.0.30319.36627

160,024

10-Apr-2020

00:06

System.ServiceModel.Discovery.dll

4.0.30319.36627

313,120

10-Apr-2020

00:06

System.ServiceModel.dll

4.0.30319.36627

6,388,328

10-Apr-2020

00:06

System.ServiceModel.Internals.dll

4.0.30319.36627

255,120

10-Apr-2020

00:06

System.ServiceModel.WasHosting.dll

4.0.30319.36627

40,432

10-Apr-2020

00:06

System.Windows.Controls.Ribbon.dll

4.0.30319.36627

751,904

10-Apr-2020

00:06

System.Xaml.dll

4.0.30319.36627

641,408

10-Apr-2020

00:06

WindowsBase.dll

4.0.30319.36627

1,242,392

10-Apr-2020

00:06

WPFFontCache_v0400.exe.mui

4.0.30319.36627

19,952

10-Apr-2020

00:29

WPFFontCache_v0400.exe.mui

4.0.30319.36627

19,952

10-Apr-2020

00:06

WPFFontCache_v0400.exe

4.0.30319.36627

26,664

10-Apr-2020

00:29

WPFFontCache_v0400.exe

4.0.30319.36627

25,424

10-Apr-2020

00:06

wpfgfx_v0400.dll

4.0.30319.36627

2,109,424

10-Apr-2020

00:29

wpfgfx_v0400.dll

4.0.30319.36627

1,649,136

10-Apr-2020

00:06

VsVersion.dll

12.0.52415.36415

18,088

10-Apr-2020

00:03

VsVersion.dll

12.0.52415.36415

18,088

10-Apr-2020

00:02

msvcp120_clr0400.dll

12.0.52480.36480

678,488

10-Apr-2020

00:03

msvcp120_clr0400.dll

12.0.52480.36480

536,856

10-Apr-2020

00:02

msvcr120_clr0400.dll

12.0.52480.36480

869,464

10-Apr-2020

00:03

msvcr120_clr0400.dll

12.0.52480.36480

875,800

10-Apr-2020

00:02

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