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Summary

This security update resolves a security feature bypass vulnerability that exists when Microsoft .NET Framework and .NET Core components do not completely validate certificates. This security update addresses the vulnerability by helping to make sure that .NET Framework and .NET Core components completely validate certificates. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-0786.

Additionally, this security update resolves a denial of service vulnerability that exists when .NET Framework and .NET core components improperly process XML documents. This update addresses the vulnerability by correcting how .NET Framework and .NET Core component applications handle XML document processing. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-0764.

Important

  • If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

Additional information about this security update

  • Enhanced Key Usage (EKU) is described in RFC 5280 in section 4.2.1.12. This extension indicates one or more purposes for which the certified public key may be used, in addition to or instead of the basic purposes that are indicated in the key usage extension. For example, a certificate that is used for the authentication of a client to a server must be configured for Client Authentication. Similarly, a certificate that is used for the authentication of a server must be configured for Server Authentication. With this change, besides requiring the appropriate client/server EKU on certificates, if the root certificate is disabled, the certificate chain validation fails.

    When certificates are used for authentication, the authenticator examines the certificate that is provided by the remote endpoint and seeks the correct purpose object identifier in Application Policies extensions. When a certificate is used for client authentication, the object identifier for Client Authentication must be present in the EKU extensions of the certificate, or authentication fails. The object identifier for Client Authentication is 1.3.6.1.5.5.7.3.2. Likewise, when a certificate is used for server authentication, the object identifier for Server Authentication must be present in the EKU extensions of the certificate, or authentication fails. The object identifier for Server Authentication is 1.3.6.1.5.5.7.3.1. Certificates that have no EKU extension continue to authenticate correctly.

    First, consider making changes to your component’s certificates to make sure that they are using the correct EKU OID attributes and are secured correctly. If you temporarily cannot access correctly reissued certificates, you can choose to opt in or out of the security change to avoid any connectivity effects. To do this, specify the following appsetting in the configuration file:

    <appSettings>
        <add key="wcf:useLegacyCertificateUsagePolicy" value="true" />
    </appSettings>

    Note Setting the value to “true” will opt out of the security changes.

  • For more information about this security update as it relates to Windows Server 2012, see the following article in the Microsoft Knowledge Base:

4055270 Security Only update for .NET Framework 3.5 SP2, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1 updates for Windows Server 2012 (KB 4055270)

How to obtain and install the update

Method 1: Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog.

Method 2: 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 will open a browser window in which you may be prompted to install an ActiveX control. Install the ActiveX control to continue.

  5. After the control is installed, you will see the Microsoft Update Catalog screen. Enter 4055270 in 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. When you have selected all the packages you need, select View Basket.

  8. Select Import to import the packages to your WSUS server.

  9. Select Close after the packages have been imported to return to WSUS.

The updates are now available for installation through WSUS.

Update deployment information

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

20180109 Security update deployment information: January 9, 2018

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 update KB 3122655.

 

File information

File hash

Package name

PackageHashSHA1

PackageHashSHA2

Windows8-RT-KB4054171-x64.msu

F32C467A5AE5924D33324A8D089F5C72EE866208

3B9E3785A1600E1A2BFC18A5C9751FF0C29282598243F3C612A73D205BD0267A

Windows8-RT-KB4054171-x86.msu

A2A9402C56EEEC4F110821EDD05C8A0C3DF02E42

3B0C011F774D1549473B1C2C54C1A0E4C4A266F0866A9581A7237775E252A60E


File attributes

The English (United States) version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time together with your current daylight-saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

For all x86-based systems

File name

File version

File size

Date

Time

smdiagnostics.dll

4.0.30319.36427

73,376

01-Dec-2017

13:05

system.activities.dll

4.0.30319.36427

1,582,768

01-Dec-2017

13:05

system.data.sqlxml.dll

4.0.30319.36427

752,320

01-Dec-2017

13:05

system.identitymodel.services.dll

4.0.30319.36427

199,904

01-Dec-2017

13:05

system.identitymodel.dll

4.0.30319.36427

1,093,832

01-Dec-2017

13:05

system.runtime.serialization.dll

4.0.30319.36427

1,060,088

01-Dec-2017

13:05

system.servicemodel.channels.dll

4.0.30319.36427

159,608

01-Dec-2017

13:05

system.servicemodel.discovery.dll

4.0.30319.36427

312,704

01-Dec-2017

13:05

system.servicemodel.internals.dll

4.0.30319.36427

254,720

01-Dec-2017

13:05

system.servicemodel.washosting.dll

4.0.30319.36427

39,656

01-Dec-2017

13:05

system.servicemodel.dll

4.0.30319.36427

6,386,368

01-Dec-2017

13:05

system.xml.dll

4.0.30319.36427

2,705,040

01-Dec-2017

13:05

msvcp120_clr0400.dll

12.0.52430.36430

536,744

12-Dec-2017

19:05

msvcr120_clr0400.dll

12.0.52430.36430

875,688

12-Dec-2017

19:05

servicemodel.mof

88,383

15-Nov-2017

00:50

servicemodel.mof.uninstall

896

15-Nov-2017

00:50

servicemonikersupport.dll

4.0.30319.36366

28,376

15-Nov-2017

00:50

For all x64-based systems

File name

File version

File size

Date

Time

msvcp120_clr0400.dll

12.0.52430.36430

678,568

12-Dec-2017

19:06

msvcr120_clr0400.dll

12.0.52430.36430

869,544

12-Dec-2017

19:06

servicemodel.mof

88,383

15-Nov-2017

00:49

servicemodel.mof.uninstall

896

15-Nov-2017

00:49

servicemonikersupport.dll

4.0.30319.36366

28,888

15-Nov-2017

00:49

smdiagnostics.dll

4.0.30319.36427

73,376

01-Dec-2017

13:13

system.activities.dll

4.0.30319.36427

1,582,768

01-Dec-2017

13:13

system.data.sqlxml.dll

4.0.30319.36427

752,320

01-Dec-2017

13:13

system.identitymodel.services.dll

4.0.30319.36427

199,904

01-Dec-2017

13:13

system.identitymodel.dll

4.0.30319.36427

1,093,832

01-Dec-2017

13:13

system.runtime.serialization.dll

4.0.30319.36427

1,060,088

01-Dec-2017

13:13

system.servicemodel.channels.dll

4.0.30319.36427

159,608

01-Dec-2017

13:13

system.servicemodel.discovery.dll

4.0.30319.36427

312,704

01-Dec-2017

13:13

system.servicemodel.internals.dll

4.0.30319.36427

254,720

01-Dec-2017

13:13

system.servicemodel.washosting.dll

4.0.30319.36427

39,656

01-Dec-2017

13:13

system.servicemodel.dll

4.0.30319.36427

6,386,368

01-Dec-2017

13:13

system.xml.dll

4.0.30319.36427

2,705,040

01-Dec-2017

13:13

smdiagnostics.dll

4.0.30319.36427

73,376

01-Dec-2017

13:05

system.activities.dll

4.0.30319.36427

1,582,768

01-Dec-2017

13:05

system.data.sqlxml.dll

4.0.30319.36427

752,320

01-Dec-2017

13:05

system.identitymodel.services.dll

4.0.30319.36427

199,904

01-Dec-2017

13:05

system.identitymodel.dll

4.0.30319.36427

1,093,832

01-Dec-2017

13:05

system.runtime.serialization.dll

4.0.30319.36427

1,060,088

01-Dec-2017

13:05

system.servicemodel.channels.dll

4.0.30319.36427

159,608

01-Dec-2017

13:05

system.servicemodel.discovery.dll

4.0.30319.36427

312,704

01-Dec-2017

13:05

system.servicemodel.internals.dll

4.0.30319.36427

254,720

01-Dec-2017

13:05

system.servicemodel.washosting.dll

4.0.30319.36427

39,656

01-Dec-2017

13:05

system.servicemodel.dll

4.0.30319.36427

6,386,368

01-Dec-2017

13:05

system.xml.dll

4.0.30319.36427

2,705,040

01-Dec-2017

13:05

msvcp120_clr0400.dll

12.0.52430.36430

536,744

12-Dec-2017

19:05

msvcr120_clr0400.dll

12.0.52430.36430

875,688

12-Dec-2017

19:05

servicemonikersupport.dll

4.0.30319.36366

28,376

15-Nov-2017

00:50

How to obtain help and support for this security update

Applies to

This article applies to the following:

 

  • Microsoft .NET Framework 4.5.2 when used with:

    • Windows Server 2012

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