KB5034171 Monthly Rollup (ESU) for Windows Server 2012 R2

KB5034171 is the cumulative monthly rollup update for Windows Server 2012 R2. It was released on 9 January 2024 under the ‘Patch Tuesday’ program of Microsoft.

Windows Server 2012 R2 reached ‘End of Support’ on 10 October 2023. Going forward, ESU or Extended Security Updates will be available for Windows Server 2012 R2.

ESU or Extended Security Updates are cumulative. You can buy ESU for Windows Server 2012 R2 on an annual renewal basis until October 2026.

KB5034171 has been superseded by KB5034819 ESU. You can read more about KB5034819 on this page.

Salient points

  • KB5034171 is the monthly rollup update (ESU or Extended Security Update) for Windows Server 2012 R2 and supersedes the KB5033420 update.
  • KB5033420 was released on 12 December 2023. You can read more about it on the KB5033420 page.
  • KB5034587 is the Servicing Stack Update that corresponds to KB5034171. The SSU was released on 9 January 2024. You would need to deploy KB5034587 before installing the KB5034171 monthly rollup update.
  • 22 security vulnerabilities affect Windows Server 2012 R2 as part of the January 2024 security report.
  • One CRITICAL security vulnerability affects Windows Server 2012 R2. You can read more about this vulnerability in the vulnerabilities section.
  • The issue with language packs continues to affect Windows Server 2012 R2. If you install a language pack after installing KB5034171, you will need to re-install the KB5034171 update. This is because installing a language pack renders the monthly rollup update infructitious.

To install KB5034171, you will need a valid key for the Extended Security Updates because the Windows Server 2012 R2 attained End of Support status on 10 October 2023.

Download KB5034171

KB5034171 is a cumulative monthly rollup update of the type of an Extended Security Update. It can be installed automatically or through a manual approach.

For automatic patching of the monthly rollup update, you could use one of the following methods:

  • Windows Update
  • WSUS or Windows Server Update Service

WSUS remains the best method to automatically import and deploy security updates or cumulative updates on Windows Servers. We strongly suggest using WSUS as the preferred method for rolling out updates.

However, you will still need a valid key to apply the Extended Security Updates on Windows Server 2012 R2.

For manual installation, you can download the offline installer files from the Microsoft Update Catalog site. Alternatively, you can use the direct download links for KB5034171 shared below.

The manual installation of KB5034171 involves the following 2 steps:

  1. Download and install KB5034587 Servicing Stack Update
  2. Download and install the KB5034171 cumulative update

For each of these updates, we have shared the download links below.

Download KB5034587

The Servicing Stack Update file for KB5034587 has a size of 10.5 MB. Servicing Stack Updates, upon installation, do not cause the server to reboot. This Servicing Stack Update was released in January 2024.

Download KB5034171

The download links for KB5034171 are shared hereunder.

The size of the offline installer file for KB5034171 is 587.4 MB.

The server will reboot post-installation of the monthly rollup update. So, we do suggest installing the cumulative update as part of an organized change process within the IT infrastructure.


There are 22 security vulnerabilities that have been disclosed for Windows Server 2012 R2 as part of the January 2024 security bulletin released by Microsoft.

We have listed the single CRITICAL threat that affects Windows Server 2012 R2 below.

CRITICAL vulnerabilities

One CRITICAL security vulnerability affects Windows Server 2012 R2. This is a ‘Security Feature Bypass’ vulnerability.

CVE detailsCVSSSeverityImpact Description
CVE-2024-206749.0CRITICALSecurity Feature BypassThe authentication feature could be bypassed as this vulnerability allows impersonation.

An authenticated attacker could exploit this vulnerability by establishing a machine-in-the-middle (MITM) attack or other local network spoofing technique, then sending a malicious Kerberos message to the client victim machine to spoof itself as the Kerberos authentication server.

The following changes are part of the KB5034171 monthly rollup update (Extended Security Updates) for Windows Server 2012 R2.

  • This update contains miscellaneous security improvements to internal Windows OS functionality.
  • This update brings in security changes for Windows Server 2012 R2.
  • The ActiveX scroll bar does not work in Internet Explorer 11 or in IE mode.

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Rajesh Dhawan

Rajesh Dhawan is a technology professional who loves to blog about smart wearables, Cloud computing and Microsoft technologies. He loves to break complex problems into manageable chunks of meaningful information.