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Applies to:

Microsoft .NET Framework 4.8

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).

Additional information about this update

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

  • 4556400 Description of the Security and Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Server 2012 (KB4556400)

How to obtain and install the update

Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to get security updates automatically, see Windows Update: FAQ.

Method 2: Microsoft Update Catalog

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

Method 3: Windows Software Update Services (WSUS)

On your WSUS server, follow these steps:

  1. Select Start, select Administrative Tools, and then select Microsoft Windows Server Update Services 3.0.

  2. Expand ComputerName, and then select Action.

  3. Select Import Updates.

  4. WSUS opens a browser window in which you may be prompted to install an ActiveX control. You must install the ActiveX control to continue.

  5. After the ActiveX control is installed, you see the Microsoft Update Catalog screen. Type 4556400 into the Search box, and then select Search.

  6. Locate the .NET Framework packages that match the operating systems, languages, and processors in your environment. Select Add to add them to your basket.

  7. After you select all the packages that you require, select View Basket.

  8. To import the packages to your WSUS server, select Import.

  9. After the packages are imported, select Close to return to WSUS.

The updates are now available for installation through WSUS.

Prerequisites

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

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.

Update replacement information

This update replaces previously released updates 4538123 and 4538157.


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

Windows Server 2012 file information

Note: The MANIFEST files (.manifest) and MUM files (.mum) that are installed are not listed.

File information

File hash information

File name

SHA1 hash

SHA256 hash

Windows8-RT-KB4552932-x64-NDP48.msu

D12D873DC8559A25B47F7E6388678B5C71FA6452

95C1BF67DF396471E7D940DABBACA84143AF06DBB2B35BC9A6D0E9CF791E7CB1

For all supported x64-based versions

File name

File version

File size

Date

Time

Platform

SP requirement

Service branch

Mscorlib.dll

4.8.4180.0

5,439,264

26-Mar-2020

23:10

x64

None

Not applicable

Normidna.nlp

Not applicable

59,342

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfc.nlp

Not applicable

47,076

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfd.nlp

Not applicable

40,566

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfkc.nlp

Not applicable

67,808

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfkd.nlp

Not applicable

61,718

02-Aug-2018

01:29

Not applicable

None

Not applicable

Aspnet_perf.dll

4.8.4075.0

49,432

23-Nov-2019

04:37

x64

SPN

AMD64_NETFX4-ASP

Aspnet_state_perf.h

Not applicable

318

23-Nov-2019

03:21

Not applicable

SPN

AMD64_NETFX4-ASP

Aspnet_state_perf.ini

Not applicable

42,996

23-Nov-2019

04:38

Not applicable

SPN

AMD64_NETFX4-ASP

Aspnet_wp.exe

4.8.4075.0

53,032

23-Nov-2019

04:37

x64

SPN

AMD64_NETFX4-ASP

Clrjit.dll

4.8.4180.0

1,365,272

26-Mar-2020

23:10

x64

None

Not applicable

Clr.dll

4.8.4180.0

11,251,192

26-Mar-2020

23:10

x64

None

Not applicable

Compatjit.dll

4.8.4180.0

1,280,800

26-Mar-2020

23:10

x64

None

Not applicable

Globalmonospace.compositefont

Not applicable

26,040

31-Jul-2019

02:08

Not applicable

SPA

AMD64_NETFX4-GLOBALMONOSP

Globalsansserif.compositefont

Not applicable

26,489

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globalserif.compositefont

Not applicable

29,779

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globaluserinterface.compositefont

Not applicable

264,986

03-Feb-2020

10:17

Not applicable

None

Not applicable

Mscordacwks.dll

4.8.4180.0

1,808,672

26-Mar-2020

23:10

x64

None

Not applicable

Mscordbi.dll

4.8.4180.0

1,662,752

26-Mar-2020

23:10

x64

None

Not applicable

Mscoreei.dll

4.8.4180.0

689,952

26-Mar-2020

23:10

x64

None

Not applicable

Penimc.dll

14.8.4180.0

19,232

26-Mar-2020

23:10

x64

None

Not applicable

Penimc2_v0400.dll

4.8.4180.0

128,288

26-Mar-2020

23:10

x64

None

Not applicable

Penimc_v0400.dll

4.8.4180.0

27,936

26-Mar-2020

23:10

x64

None

Not applicable

Peverify.dll

4.8.4180.0

273,184

26-Mar-2020

23:10

x64

None

Not applicable

Presentationframework-systemdata.dll

4.8.4180.0

25,376

26-Mar-2020

23:11

x86

None

Not applicable

Presentationframework.dll

4.8.4180.0

6,271,264

26-Mar-2020

23:11

x86

None

Not applicable

Presentationhost_v0400.dll.mui

4.8.4180.0

85,280

26-Mar-2020

23:10

Not applicable

None

Not applicable

Presentationhost_v0400.dll

4.8.4180.0

310,048

26-Mar-2020

23:10

x64

None

Not applicable

Presentationnative_v0400.dll

4.8.4180.0

1,171,744

26-Mar-2020

23:10

x64

None

Not applicable

Reachframework.dll

4.8.4110.0

677,656

04-Dec-2019

02:55

x86

None

Not applicable

Servicemodel.mof

Not applicable

88,383

03-Feb-2020

13:12

Not applicable

None

Not applicable

Servicemodel.mof.uninstall

Not applicable

896

03-Feb-2020

13:12

Not applicable

None

Not applicable

Servicemonikersupport.dll

4.8.4180.0

35,104

26-Mar-2020

23:10

x64

None

Not applicable

Smdiagnostics.dll

4.8.4180.0

73,880

26-Mar-2020

23:11

x86

None

Not applicable

_smsvchostperfcounters.h

Not applicable

702

06-Dec-2019

22:20

Not applicable

None

Not applicable

_smsvchostperfcounters.ini

Not applicable

133,894

07-Dec-2019

06:04

Not applicable

None

Not applicable

_smsvchostperfcounters_d.ini

Not applicable

39

09-Nov-2019

00:37

Not applicable

None

Not applicable

Smsvchost.exe

4.8.4121.0

139,056

07-Dec-2019

06:03

x86

None

Not applicable

Smsvchost.exe.config

Not applicable

2,262

21-Nov-2019

02:58

Not applicable

None

Not applicable

Sos.dll

4.8.4180.0

929,056

26-Mar-2020

23:10

x64

None

Not applicable

System.activities.presentation.dll

4.8.4150.0

2,127,128

09-Jan-2020

19:46

x86

None

Not applicable

System.activities.dll

4.8.4180.0

1,534,312

26-Mar-2020

23:11

x86

None

Not applicable

System.core.dll

4.8.4180.0

1,556,832

26-Mar-2020

23:11

x86

None

Not applicable

System.identitymodel.services.dll

4.8.4180.0

199,152

26-Mar-2020

23:11

x86

None

Not applicable

System.identitymodel.dll

4.8.4180.0

1,094,504

26-Mar-2020

23:11

x86

None

Not applicable

System.net.sockets.dll

4.8.4121.0

30,360

07-Dec-2019

06:03

x86

None

Not applicable

System.runtime.serialization.dll

4.8.4180.0

1,054,872

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.channels.dll

4.8.4180.0

158,704

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.discovery.dll

4.8.4180.0

309,024

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.internals.dll

4.8.4180.0

254,096

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.washosting.dll

4.8.4180.0

40,736

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.dll

4.8.4180.0

6,389,336

26-Mar-2020

23:11

x86

None

Not applicable

System.web.applicationservices.dll

4.8.4075.0

71,512

23-Nov-2019

05:17

x86

None

Not applicable

System.web.extensions.dll

4.8.4075.0

1,849,992

23-Nov-2019

05:17

x86

None

Not applicable

System.windows.controls.ribbon.dll

4.8.4180.0

751,392

26-Mar-2020

23:11

x86

None

Not applicable

System.windows.forms.dll

4.8.4150.0

5,921,416

09-Jan-2020

19:46

x86

None

Not applicable

System.workflow.activities.dll

4.8.4110.0

1,051,112

04-Dec-2019

02:55

x86

None

Not applicable

System.workflow.componentmodel.dll

4.8.4110.0

1,557,272

04-Dec-2019

02:55

x86

None

Not applicable

System.workflow.runtime.dll

4.8.4110.0

503,064

04-Dec-2019

02:55

x86

None

Not applicable

System.xaml.dll

4.8.4180.0

640,056

26-Mar-2020

23:11

x86

None

Not applicable

System.dll

4.8.4001.0

3,560,496

24-Jul-2019

02:58

x86

None

Not applicable

Uiautomationclientsideproviders.dll

4.8.4180.0

361,760

26-Mar-2020

23:11

x86

None

Not applicable

Uiautomationclient.dll

4.8.4180.0

178,464

26-Mar-2020

23:11

x86

None

Not applicable

Uiautomationprovider.dll

4.8.4180.0

49,648

26-Mar-2020

23:11

x86

None

Not applicable

Uiautomationtypes.dll

4.8.4180.0

223,512

26-Mar-2020

23:11

x86

None

Not applicable

Webengine4.dll

4.8.4075.0

682,776

23-Nov-2019

04:37

x64

None

Not applicable

Webengine.dll

4.8.4075.0

28,952

23-Nov-2019

04:37

x64

None

Not applicable

Windowsbase.dll

4.8.4180.0

1,306,392

26-Mar-2020

23:11

x86

None

Not applicable

Windowsformsintegration.dll

4.8.4150.0

105,240

09-Jan-2020

19:46

x86

None

Not applicable

Workflowservicehostperformancecounters.dll

4.8.4110.0

102,672

04-Dec-2019

02:54

x64

None

Not applicable

Wpfgfx_v0400.dll

4.8.4180.0

2,058,016

26-Mar-2020

23:10

x64

None

Not applicable

Globalmonospace.compositefont

Not applicable

26,040

03-Feb-2020

13:25

Not applicable

None

Not applicable

Globalsansserif.compositefont

Not applicable

26,489

03-Feb-2020

13:25

Not applicable

None

Not applicable

Globalserif.compositefont

Not applicable

29,779

03-Feb-2020

13:25

Not applicable

None

Not applicable

Globaluserinterface.compositefont

Not applicable

264,986

03-Feb-2020

13:25

Not applicable

None

Not applicable

Presentationcore.dll

4.8.4180.0

3,652,384

26-Mar-2020

23:10

x64

None

Not applicable

System.data.dll

4.8.4121.0

3,541,488

07-Dec-2019

06:00

x64

None

Not applicable

System.printing.dll

4.8.4110.0

400,152

04-Dec-2019

02:54

x64

None

Not applicable

System.web.dll

4.8.4075.0

5,403,624

23-Nov-2019

04:37

x64

None

Not applicable

Presentationframework-systemdata.dll

4.8.4180.0

25,376

26-Mar-2020

23:11

x86

None

Not applicable

Presentationframework.dll

4.8.4180.0

6,271,264

26-Mar-2020

23:11

x86

None

Not applicable

Reachframework.dll

4.8.4110.0

677,656

04-Dec-2019

02:55

x86

None

Not applicable

Smdiagnostics.dll

4.8.4180.0

73,880

26-Mar-2020

23:11

x86

None

Not applicable

Smsvchost.exe

4.8.4121.0

139,056

07-Dec-2019

06:03

x86

None

Not applicable

System.activities.presentation.dll

4.8.4150.0

2,127,128

09-Jan-2020

19:46

x86

None

Not applicable

System.activities.dll

4.8.4180.0

1,534,312

26-Mar-2020

23:11

x86

None

Not applicable

System.core.dll

4.8.4180.0

1,556,832

26-Mar-2020

23:11

x86

None

Not applicable

System.identitymodel.services.dll

4.8.4180.0

199,152

26-Mar-2020

23:11

x86

None

Not applicable

System.identitymodel.dll

4.8.4180.0

1,094,504

26-Mar-2020

23:11

x86

None

Not applicable

System.net.sockets.dll

4.8.4121.0

30,360

07-Dec-2019

06:03

x86

None

Not applicable

System.runtime.serialization.dll

4.8.4180.0

1,054,872

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.channels.dll

4.8.4180.0

158,704

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.discovery.dll

4.8.4180.0

309,024

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.internals.dll

4.8.4180.0

254,096

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.washosting.dll

4.8.4180.0

40,736

26-Mar-2020

23:11

x86

None

Not applicable

System.servicemodel.dll

4.8.4180.0

6,389,336

26-Mar-2020

23:11

x86

None

Not applicable

System.web.applicationservices.dll

4.8.4075.0

71,512

23-Nov-2019

05:17

x86

None

Not applicable

System.web.extensions.dll

4.8.4075.0

1,849,992

23-Nov-2019

05:17

x86

None

Not applicable

System.windows.controls.ribbon.dll

4.8.4180.0

751,392

26-Mar-2020

23:11

x86

None

Not applicable

System.windows.forms.dll

4.8.4150.0

5,921,416

09-Jan-2020

19:46

x86

None

Not applicable

System.workflow.activities.dll

4.8.4110.0

1,051,112

04-Dec-2019

02:55

x86

None

Not applicable

System.workflow.componentmodel.dll

4.8.4110.0

1,557,272

04-Dec-2019

02:55

x86

None

Not applicable

System.workflow.runtime.dll

4.8.4110.0

503,064

04-Dec-2019

02:55

x86

None

Not applicable

System.xaml.dll

4.8.4180.0

640,056

26-Mar-2020

23:11

x86

None

Not applicable

System.dll

4.8.4001.0

3,560,496

24-Jul-2019

02:58

x86

None

Not applicable

Uiautomationclientsideproviders.dll

4.8.4180.0

361,760

26-Mar-2020

23:11

x86

None

Not applicable

Uiautomationclient.dll

4.8.4180.0

178,464

26-Mar-2020

23:11

x86

None

Not applicable

Uiautomationprovider.dll

4.8.4180.0

49,648

26-Mar-2020

23:11

x86

None

Not applicable

Uiautomationtypes.dll

4.8.4180.0

223,512

26-Mar-2020

23:11

x86

None

Not applicable

Windowsbase.dll

4.8.4180.0

1,306,392

26-Mar-2020

23:11

x86

None

Not applicable

Windowsformsintegration.dll

4.8.4150.0

105,240

09-Jan-2020

19:46

x86

None

Not applicable

Mscorlib.dll

4.8.4180.0

5,678,576

26-Mar-2020

23:11

x86

None

Not applicable

Normidna.nlp

Not applicable

59,342

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfc.nlp

Not applicable

47,076

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfd.nlp

Not applicable

40,566

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfkc.nlp

Not applicable

67,808

02-Aug-2018

01:29

Not applicable

None

Not applicable

Normnfkd.nlp

Not applicable

61,718

02-Aug-2018

01:29

Not applicable

None

Not applicable

Aspnet_perf.dll

4.8.4075.0

43,800

23-Nov-2019

05:17

x86

SPN

X86_NETFX4-ASP

Aspnet_state_perf.h

Not applicable

318

23-Nov-2019

03:12

Not applicable

SPN

X86_NETFX4-ASP

Aspnet_state_perf.ini

Not applicable

42,996

23-Nov-2019

05:18

Not applicable

SPN

X86_NETFX4-ASP

Aspnet_wp.exe

4.8.4075.0

47,608

23-Nov-2019

05:17

x86

SPN

X86_NETFX4-ASP

Clrjit.dll

4.8.4180.0

561,648

26-Mar-2020

23:11

x86

None

Not applicable

Clr.dll

4.8.4180.0

8,044,832

26-Mar-2020

23:11

x86

None

Not applicable

Globalmonospace.compositefont

Not applicable

26,040

31-Jul-2019

02:08

Not applicable

SPA

X86_NETFX4-GLOBALMONOSP

Globalsansserif.compositefont

Not applicable

26,489

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globalserif.compositefont

Not applicable

29,779

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globaluserinterface.compositefont

Not applicable

264,986

03-Feb-2020

10:17

Not applicable

None

Not applicable

Mscordacwks.dll

4.8.4180.0

1,315,104

26-Mar-2020

23:11

x86

None

Not applicable

Mscordbi.dll

4.8.4180.0

1,196,320

26-Mar-2020

23:11

x86

None

Not applicable

Mscoreei.dll

4.8.4180.0

581,920

26-Mar-2020

23:11

x86

None

Not applicable

Penimc.dll

14.8.4180.0

19,232

26-Mar-2020

23:11

x86

None

Not applicable

Penimc2_v0400.dll

4.8.4180.0

107,504

26-Mar-2020

23:11

x86

None

Not applicable

Penimc_v0400.dll

4.8.4180.0

26,096

26-Mar-2020

23:11

x86

None

Not applicable

Peverify.dll

4.8.4180.0

190,232

26-Mar-2020

23:11

x86

None

Not applicable

Presentationhost_v0400.dll.mui

4.8.4180.0

85,272

26-Mar-2020

23:11

Not applicable

None

Not applicable

Presentationhost_v0400.dll

4.8.4180.0

241,648

26-Mar-2020

23:11

x86

None

Not applicable

Presentationnative_v0400.dll

4.8.4180.0

930,808

26-Mar-2020

23:11

x86

None

Not applicable

Servicemonikersupport.dll

4.8.4180.0

32,272

26-Mar-2020

23:11

x86

None

Not applicable

Smsvchost.exe.config

Not applicable

2,262

25-Jul-2019

21:42

Not applicable

None

Not applicable

Sos.dll

4.8.4180.0

774,944

26-Mar-2020

23:11

x86

None

Not applicable

System.core.dll

4.8.4180.0

1,556,832

26-Mar-2020

23:11

x86

None

Not applicable

System.web.extensions.dll

4.8.4075.0

1,849,992

23-Nov-2019

05:17

x86

None

Not applicable

Webengine4.dll

4.8.4075.0

572,184

23-Nov-2019

05:17

x86

None

Not applicable

Webengine.dll

4.8.4075.0

26,904

23-Nov-2019

05:17

x86

None

Not applicable

Workflowservicehostperformancecounters.dll

4.8.4110.0

89,368

04-Dec-2019

02:55

x86

None

Not applicable

Wpfgfx_v0400.dll

4.8.4180.0

1,626,608

26-Mar-2020

23:11

x86

None

Not applicable

Globalmonospace.compositefont

Not applicable

26,040

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globalsansserif.compositefont

Not applicable

26,489

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globalserif.compositefont

Not applicable

29,779

31-Jul-2019

02:08

Not applicable

None

Not applicable

Globaluserinterface.compositefont

Not applicable

264,986

03-Feb-2020

10:17

Not applicable

None

Not applicable

Presentationcore.dll

4.8.4180.0

3,676,440

26-Mar-2020

23:11

x86

None

Not applicable

System.data.dll

4.8.4121.0

3,474,720

07-Dec-2019

06:03

x86

None

Not applicable

System.printing.dll

4.8.4110.0

399,640

04-Dec-2019

02:55

x86

None

Not applicable

System.web.dll

4.8.4075.0

5,416,728

23-Nov-2019

05:17

x86

None

Not applicable

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