Security and Quality Rollup for .NET Framework 4.8 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB4506993)

A remote code execution vulnerability exists in .NET software when the software fails to check the source markup of a file. An Authentication Bypass vulnerability exists in WCF and WIF, allowing signing of SAML tokens with arbitrary symmetric keys. This vulnerability allows an attacker to impersonate another user. The vulnerability exists in WCF, WIF 3.5 and above in .NET Framework, WIF 1.0 component in Windows, WIF Nuget package, and WIF implementation in Sharepoint. An information disclosure vulnerability exists when Exchange and Azure Active Directory allow creation of entities with Display Names having non-printable characters.

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

• CVE-2019-1113
• CVE-2019-1006
• CVE-2019-1083

Important

• As a reminder to advanced IT administrators, updates to .NET Framework 3.5 for Windows 8.1 and Windows Server 2012 R2 should only be applied on systems where .NET Framework 3.5 is present and enabled. Customers who attempt to pre-install updates to .NET Framework 3.5 to offline images that do not contain the .NET Framework 3.5 product enabled will expose these systems to failures to enable .NET Framework 3.5 after the systems are online. For more extensive information about deploying .NET Framework 3.5, see Microsoft .NET Framework 3.5 Deployment Considerations.
• All updates for Windows 8.1, Windows RT 8.1, and Windows Server 2012 R2 require that update KB 2919355 is installed. We recommend that you install update KB 2919355 on your Windows 8.1-based, Windows RT 8.1-based, or Windows Server 2012 R2-based computer so that you receive updates in the future.
• 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.

• 4507422 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 8.1, RT 8.1, and Server 2012 R2 (KB4507422)

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.

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 4507422 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.

Update deployment information

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

20190709 Security update deployment information: July 9, 2019

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 4499408 and 4503867.

• Protect yourself online: Windows Security support
• Learn how we guard against cyber threats: Microsoft Security