April 9, 2019—KB4493448 (Security-only update)

Applies to: Windows 7 Service Pack 1Windows Server 2008 R2 Service Pack 1

Improvements and fixes


This security update includes quality improvements. Key changes include:

  • Provides protections against Spectre Variant 2 (CVE-2017-5715) and Meltdown (CVE-2017-5754) for VIA-based computers. These protections are enabled by default for the Windows Client, but disabled by default for Windows Server. For Windows Client (IT Pro) guidance, follow the instructions in KB4073119. For Windows Server guidance, follow the instructions in KB4072698. Use these guidance documents to enable or disable these mitigations for VIA-based computers.
  • Addresses an issue in which netdom.exe fails to run, and the error, “The command failed to complete successfully” appears.
  • Addresses an issue that may cause authentication issues for Internet Explorer 11 and other applications that use WININET.DLL. This occurs when two or more people use the same user account for multiple, concurrent login sessions on the same Windows Server machine, including Remote Desktop Protocol (RDP) and Terminal Server logons.
  • Addresses an issue that may cause compound document (OLE) server applications to display embedded objects incorrectly if you use the PatBlt API to place embedded objects into the Windows Metafile (WMF).

  • Security updates to Windows Kernel, Windows Server, Graphics Component, Windows Input and Composition, Windows Datacenter Networking, Windows MSXML, and the Microsoft JET Database Engine.

For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.

Known issues in this update


Symptom Workaround
After installing this update, some customers report that authentication fails for services that require unconstrained delegation after the Kerberos ticket expires (the default is 10 hours). For example, the SQL server service fails.

To mitigate this issue, use one of the following options:

Option 1: Purge the Kerberos tickets on the application server. After the Kerberos ticket expires, the issue will occur again, and you must purge the tickets again.

Option 2: If purging does not mitigate the issue, restart the application; for example, restart the Internet Information Services (IIS) app pool associated with the SQL server.

Option 3: Use constrained delegation.

Microsoft is working on a resolution and will provide an update in an upcoming release.
Microsoft and Sophos have identified an issue on devices with Sophos Endpoint Protection installed and managed by either Sophos Central or Sophos Enterprise Console (SEC) that may cause the system to become unresponsive upon restart after installing this update.

Microsoft has temporarily blocked devices from receiving this update if the Sophos Endpoint is installed until a solution is available. 

Guidance for Sophos Endpoint and Sophos Enterprise Console customers can be found in the Sophos support article.

Microsoft and Avira have identified an issue on devices with Avira antivirus software installed that may cause the system to become unresponsive upon restart after installing this update.

Microsoft has temporarily blocked devices from receiving this update if Avira antivirus software is installed.

We are presently investigating this issue with Avira and will provide an update when available.
Microsoft and Avast have identified an issue on devices running Avast for Business, Avast CloudCare, and AVG Business Edition antivirus software after you install this update and restart. Devices may become unresponsive at the login or Welcome screen. Additionally, you may be unable to log in or log in after an extended period of time. Avast has released emergency updates to address this issue. For more information and AV update schedule, see the Avast support KB article.

How to get this update


Before installing this update

Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes. 

If you are using Windows Update, the latest SSU (KB4490628) will be offered to you automatically. To get the standalone package for the latest SSU, go to the Microsoft Update Catalog

Install this update

This update is now available for installation through WSUS. To get the standalone package for this update, go to the Microsoft Update Catalog website.

File information

For a list of the files that are provided in this update, download the file information for update 4493448