Overview

On February 12, NSFOCUS CERT detected that Microsoft released a security update patch for February, which fixed 63 security issues involving widely used products such as Windows, Microsoft Office, Azure, Apps, and Microsoft Visual Studio, including high-risk vulnerabilities such as privilege escalation and remote code execution.

Among the vulnerabilities fixed in Microsoft’s monthly update this month, 4 are critical and
(Important) There are 56 vulnerabilities. These included 2 detected exploits:

Windows Storage Permission Escalation Vulnerability (CVE-2025-21391)

WinSock Elevation of Privilege Vulnerability for Windows Ancillary Function Driver (CVE-2025-21418)

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

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

Key Vulnerabilities

Screen out the vulnerabilities with great impact in this update according to product popularity and vulnerability importance. Please pay attention to them:

WinSock Elevation of Privilege Vulnerability of Windows Accessibility Driver (CVE-2025-21418):

A elevation of privilege vulnerability exists in WinSock of the Windows helper driver, where an authenticated local attacker can trigger a heap buffer overflow to gain SYSTEM privileges for the system due to boundary errors in the Winsock’s helper driver. 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-2025-21418

Windows Storage Permission Escalation Vulnerability (CVE-2025-21391):

A elevation of privilege vulnerability is present in the Windows storage where a local attacker can execute code with SYSTEM privileges on the target system to delete arbitrary files due to improper link parsing in the Windows storage. The vulnerability has been exploited, with a CVSS score of 7.1.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21391

Windows Lightweight Directory Access Protocol (LDAP) Remote Code Execution Vulnerability (CVE-2025-21376):

Windows LDAP has a remote code execution vulnerability. An unauthenticated attacker can cause buffer overflow and execute arbitrary code on the target system after winning the competition condition by sending a special LDAP request. The CVSS score was 8.1.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21376

Microsoft Excel Remote Code Execution Vulnerability (CVE-2025-21381):

Microsoft Excel has a remote code execution vulnerability. Due to unreliable pointer de-reference in Microsoft Excel, remote attackers can execute arbitrary code on the target system by coaxing the victim to open a special excel file. The CVSS score was 7.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21381

DHCP Client Service Remote Code Execution Vulnerability (CVE-2025-21379):

The DHCP client service has a remote code execution vulnerability. Due to the reuse after release in the DHCP client service, attackers in the local network can launch man-in-the-middle attacks and execute codes with SYSTEM privileges on the target system. The CVSS score was 7.1.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21379

NTLM Hash Leak Spoofing Vulnerability (CVE-2025-21377):

NTLM has a hash leak spoofing vulnerability. An attacker can obtain the NTLMV2 hash by tricking a user to click on a special link, and then log in to the system as the user. The vulnerability has been publicly disclosed with a CVSS score of 6.5.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21377

Microsoft SharePoint Server Remote Code Execution Vulnerability (CVE-2025-21400):

Microsoft SharePoint Server has a remote code execution vulnerability where an attacker can spoof a victim client into connecting to a malicious server and execute arbitrary code on the target system due to improper authorization in the Microsoft SharePoint Server. The CVSS score was 8.0.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21400

Windows Disk Cleanup Tool Permission Escalation Vulnerability (CVE-2025-21420):

A elevation of privilege vulnerability is present in the Windows Disk Cleanup Tool, which can be exploited by a local attacker to gain SYSTEM privileges on the target system due to improper link resolution in the Windows Disk Cleanup Tool. The CVSS score is 7.8.

Official Announcement Link:

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21420

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-Feb

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.

Appendix

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 Security Update Notification in February 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/microsoft-security-update-notification-in-february-of-high-risk-vulnerabilities-in-multiple-products/