October 10, 2023—KB5031377 (OS Build 10240.20232)

2023-10-1007:00:00

Microsoft

support.microsoft.com

windows update

security issues

daylight saving time

ukraine capital

cve-2023-44487

registry key

rst_streams

security update guide

9.8 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

7.5 High

AI Score

Confidence

High

0.732 High

EPSS

Percentile

98.1%

JSON

October 10, 2023—KB5031377 (OS Build 10240.20232)

12/8/20
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. For an overview of Windows 10, version 1507, see its update history page.

Highlights

This update supports daylight saving time (DST) changes in Greenland.
This update addresses security issues for your Windows operating system.

Improvements

This security update includes quality improvements. When you install this KB:

This update changes the spelling of Ukraine’s capital from Kiev to Kyiv.
This update addresses an issue that affects external binding. It fails. This occurs after you install Windows updates dated May 2023 or later. Because of this, there are issues that affect LDAP queries and authentication.
To protect against CVE-2023-44487, you should install the latest Windows update. Based on your use case, you can also set the limit of the RST_STREAMS per minute using the new registry key in this update. You can create the DWORD registry values in the table below under the following registry key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\ParametersThese keys are not present by default when you install this KB. You can create them as required to set new values for your environment.Registry key|Default value|Valid value range|Registry key function
—|—|—|—
Http2MaxClientResetsPerMinute| 500| 0–65535| Sets the allowed number of resets (RST_STREAMS) per minute for a connection. When you reach this limit, the connection ends.
If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.For more information about security vulnerabilities, please refer to the new Security Update Guide website and the October 2023 Security Updates.

Known issues in this update

Microsoft is not currently aware of any issues with this update.

How to get this update

Before installing this updateMicrosoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU and applying Microsoft security updates. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions. If you are using Windows Update, the latest SSU (KB5031466) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.Install this update****Release Channel	Available	Next Step
Windows Update and Microsoft Update	Yes	None. This update will be downloaded and installed automatically from Windows Update.
Windows Update for Business	Yes	None. This update will be downloaded and installed automatically from Windows Update in accordance with configured policies.
Microsoft Update Catalog	Yes	To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS)	Yes	This update will automatically sync with WSUS if you configure Products and Classifications as follows:Product: Windows 10Classification: Security Updates File informationFor a list of the files that are provided in this update, download the file information for cumulative update 5031377.