Overview

On January 14, NSFOCUS CERT detected that Microsoft released a security update patch for January, which fixed 159 security problems in widely used products such as Windows, Microsoft Office, Microsoft Visual Studio, Azure, Microsoft Dynamics, and Microsoft Edge. This includes high-risk vulnerabilities such as privilege escalation and remote code execution.

Among the vulnerabilities fixed in Microsoft’s update this month, 12 are critical in severity, 147 are important in severity, 3 vulnerabilities could be exploited in the field:

Windows Hyper-V NT Kernel Integration VSP Privilege Escalation Vulnerability (CVE-2025-21333/CVE-2025-21334/CVE-2025-21335)

Please update patches for protection as soon as possible. For a complete list of vulnerabilities, check the appendix.

Reference link: https://msrc.microsoft.com/update-guide/en-us/releaseNote/2025-Jan

Key Vulnerabilities

Windows Hyper-V NT Kernel Integration VSP Permission Escalation Vulnerability (CVE-2025-21333/CVE-2025-21334/CVE-2025-21335):

A privilege escalation vulnerability exists in Windows Hyper-V NT Kernel Integration VSP where an authenticated local attacker can trigger a heap buffer overflow due to boundary errors in the component, thereby gaining SYSTEM privileges on the system. The vulnerability has been exploited, with a CVSS score of 7.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21333

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21334

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21335

Windows OLE Remote Code Execution Vulnerability (CVE-2025-21298):

Windows OLE has a remote code execution vulnerability, where an unauthenticated attacker sends special emails to the affected system by using Outlook and can execute codes remotely without user interaction. The CVSS score is 9.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21298

Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability (CVE-2025-21307):

The Windows Reliable Multicast Transport Driver (RMCAST) has a remote code execution vulnerability that can be exploited by an unauthenticated attacker via a Windows Pragmatic General Multicast (PGM) open socket sending special packets to the server in order to execute remote code on the target system. The CVSS score is 9.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21307

Windows NTLM V1 privilege escalation vulnerability (CVE-2025-21311):

There is a privilege escalation vulnerability in Windows NTLM V1. Due to the incorrect implementation of authentication algorithm in Windows NTLM V1, unauthenticated attackers can exploit it through the network under low complexity conditions, thus elevating the privileges of the target system. The CVSS score is 9.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21311

Microsoft Excel Remote Code Execution Vulnerability (CVE-2025-21354/CVE-2025-21362):

Microsoft Excel has a remote code execution vulnerability. Due to illegal pointer de-reference and reuse after release in Excel, the attacker can induce the victim to download and open an Excel file through social engineering to execute arbitrary code. The CVSS score is 7.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21354

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21362

Windows Remote Desktop Service remote code execution vulnerability (CVE-2025-21297):

The Windows Remote Desktop Service has a remote code execution vulnerability. Since sensitive data in the Windows Remote Desktop Service is stored in an incorrectly locked memory, an unauthenticated attacker can connect to a system with the role of remote desktop gateway and send special requests to win competition conditions, thus executing arbitrary codes on the target system. The CVSS score is 8.1.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21297

BranchCache Remote Code Execution Vulnerability (CVE-2025-21296):

BranchCache has a remote code execution vulnerability. Due to an after-release reuse error in BranchCache, unauthenticated attackers on the local network can send special requests to win competition conditions and execute arbitrary codes on the target system. The CVSS score is 7.5.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21296

Scope of Impact

The following are some affected product versions that focus on vulnerabilities. For the scope of other products affected by vulnerabilities, please refer to the official announcement link:

Mitigation

At present, Microsoft has officially released security patches to fix the above vulnerabilities for supported product versions. It is strongly recommended that affected users install patches as soon as possible for protection.

Download link of the official website: https://msrc.microsoft.com/update-guide/en-us/releaseNote/2025-Jan

Note: Patch update of Windows Update may fail due to network problems, computer environment problems and other reasons. After installing the patch, users should check whether the patch is successfully updated in time.

For updates that have not been successfully installed, you can click the name of the update to visit Microsoft’s official download page. It is recommended that users click on the link on this page to go to the “Microsoft Update Catalog” website to download and install the standalone package.

Appendix: Vulnerability List

Statement

This advisory is only used to describe a potential risk. NSFOCUS does not provide any commitment or promise on this advisory. NSFOCUS and the author will not bear any liability for any direct and/or indirect consequences and losses caused by transmitting and/or using this advisory. NSFOCUS reserves all the rights to modify and interpret this advisory. Please include this statement paragraph when reproducing or transferring this advisory. Do not modify this advisory, add/delete any information to/from it, or use this advisory for commercial purposes without permission from NSFOCUS.

About NSFOCUS

NSFOCUS, a pioneering leader in cybersecurity, is dedicated to safeguarding telecommunications, Internet service providers, hosting providers, and enterprises from sophisticated cyberattacks.

Founded in 2000, NSFOCUS operates globally with over 4000 employees at two headquarters in Beijing, China, and Santa Clara, CA, USA, and over 50 offices worldwide. It has a proven track record of protecting over 25% of the Fortune Global 500 companies, including four of the five largest banks and six of the world’s top ten telecommunications companies.

Leveraging technical prowess and innovation, NSFOCUS delivers a comprehensive suite of security solutions, including the Intelligent Security Operations Platform (ISOP) for modern SOC, DDoS Protection, Continuous Threat Exposure Management (CTEM) Service and Web Application and API Protection (WAAP). All the solutions and services are augmented by the Security Large Language Model (SecLLM), ML, patented algorithms and other cutting-edge research achievements developed by NSFOCUS.

The post Microsoft’s January Security Update of High-Risk Vulnerabilities in Multiple Products appeared first on NSFOCUS, Inc., a global network and cyber security leader, protects enterprises and carriers from advanced cyber attacks..

*** This is a Security Bloggers Network syndicated blog from NSFOCUS, Inc., a global network and cyber security leader, protects enterprises and carriers from advanced cyber attacks. authored by NSFOCUS. Read the original post at: https://nsfocusglobal.com/microsofts-january-security-update-of-high-risk-vulnerabilities-in-multiple-products/