October 8, 2019—KB4520004 (OS Build 16299.1451)

ReminderMarch 12 and April 9 were the last two Delta updates for Windows 10, version 1709. Security and quality updates will continue to be available via the express and full cumulative update packages. For more information on this change please visit our blog.

Reminder Windows 10, version 1709, reached end of service on April 9, 2019 for devices running Windows 10 Home, Pro, Pro for Workstation, and IoT Core editions. These devices will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

IMPORTANTWindows 10 Enterprise, Education, and IoT Enterprise editions will continue to receive servicing for 12 months at no cost per the lifecycle announcement on October 2018.

ePub support ending in Microsoft EdgeMicrosoft Edge will end support for e-books that use the .epub file extension over the next several months. For more information, see Download an ePub app to keep reading e-books.

For more information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the following article.

Highlights

• Updates to improve security when using Internet Explorer and Microsoft Edge.
• Updates for verifying user names and passwords.
• Updates for storing and managing files.

Improvements and fixes

This security update includes quality improvements. Key changes include:

• Addresses an issue in the Keyboard Lockdown Subsystem that may not filter key input correctly.
• Addresses an issue with the Bluetooth hardening updates, released August 13, 2019, that may cause a “0x133 DPC_WATCHDOG_VIOLATION” error.
• Addresses an issue in security bulletin CVE-2019-1318 that may cause client or server computers that don’t support Extended Master Secret (EMS) RFC 7627 to have increased connection latency and CPU utilization. This issue occurs while performing full Transport Layer Security (TLS) handshakes from devices that don’t support EMS, especially on servers. EMS support has been available for all the supported versions of Windows since calendar year 2015 and is being incrementally enforced by the installation of the October 8, 2019 and later monthly updates.
• Addresses an issue with applications and printer drivers that utilize the Windows JavaScript engine (jscript.dll) for processing print jobs.
• Security updates to Windows Shell, Microsoft Edge, Internet Explorer, Windows App Platform and Frameworks, Windows Cryptography, Windows Authentication, Windows Datacenter Networking, Windows Storage and Filesystems, Microsoft JET Database Engine, Windows Kernel, Microsoft Scripting Engine, and Windows Server.
  If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.

Known issues in this update

• Perform the operation from a process that has administrator privilege.

• Perform the operation from a node that doesn’t have CSV ownership.
  Microsoft is working on a resolution and will provide an update in an upcoming release.
  When setting up a new Windows device during the Out of Box Experience (OOBE), you might be unable to create a local user when using Input Method Editor (IME). This issue might affect you if you are using the IME for Chinese, Japanese, or Korean languages.Note This issue does not affect using a Microsoft Account during OOBE.| This issue is resolved in KB4534318.
  Updates for Windows released October 8, 2019 or later provide protections, tracked by CVE-2019-1318, against an attack that could allow unauthorized access to information or data within TLS connections. This type of attack is known as a man-in-the-middle exploit. Windows might fail to connect to TLS clients and servers that do not support Extended Master Secret for resumption (RFC 7627). Lack of RFC support might cause one or more of the following errors or logged events:

• “The request was aborted: Could not create SSL/TLS secure Channel”

• SCHANNEL event 36887 is logged in the System event log with the description, “A fatal alert was received from the remote endpoint. The TLS protocol defined fatal alert code is 20.​”
  | For information, see KB4528489.

How to get this update