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Security Advisory

Microsoft Updates Patch Tuesday for Feb 2025; Address 67 Vulnerabilities, Includes 2 Exploited Zero-Days 

Summary

Microsoft’s February 2025 Patch Tuesday addresses multiple security vulnerabilities, including four zero-days, with two actively exploited in the wild. This update covers a total of 67 security flaws, with three classified as critical Remote Code Execution (RCE) vulnerabilities.  

Microsoft  issued a revision for an older zero-day that threatens the latest Windows desktop and server versions.

OEM Microsoft 
Severity Critical 
Date of Announcement 2025-02-11
No. of Vulnerabilities Patched 67 
Actively Exploited Yes 
Exploited in Wild Yes 
Advisory Version 1.0 

Overview 

The affected products include Windows, Microsoft Office, Microsoft Surface, and various network services. Organizations are strongly advised to apply these patches immediately to mitigate security risks and potential cyberattacks. 

  • 63 Microsoft CVEs addressed 
  • 4 non-Microsoft CVEs included 

The highlighted vulnerabilities include 4 zero-day flaws, 2 of which are currently being actively exploited. 

Vulnerability Name CVE ID Product Affected Severity CVSS Score 
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability CVE-2025-21418 Windows High 7.8 
Windows Storage Elevation of Privilege Vulnerability  CVE-2025-21391 Windows High 7.1 
Microsoft Surface Security Feature Bypass Vulnerability CVE-2025-21194 Windows High  7.1 
NTLM Hash Disclosure Spoofing Vulnerability CVE-2025-21377 Windows Medium  6.5 

Technical Summary 

CVE ID System Affected Vulnerability Details Impact 
  CVE-2025-21418  Windows server and Windows 10 & 11  Windows ancillary function driver for winsock elevation of privilege vulnerability enables attackers to escalate privileges to SYSTEM level. Specific exploitation details are not disclosed.    Unauthorized access with SYSTEM privileges.  
  CVE-2025-21391  Windows server and Windows 10 & 11 Windows storage elevation of privilege vulnerability allows attackers to delete targeted files on a system, potentially leading to service unavailability. Does not expose confidential data.    Deletion of critical data, leading to service disruption. 
  CVE-2025-21194    Microsoft Surface    Microsoft surface security feature bypass vulnerability allows attackers to bypass UEFI protections, compromising the secure kernel. Likely related to “PixieFail” vulnerabilities affecting the IPv6 network stack in Tianocore’s EDK II firmware.    Bypass of security features, potentially compromising system integrity. 
 CVE-2025-21377  Windows server and Windows 10 & 11 NTLM hash disclosure spoofing vulnerability exposes NTLM hashes when a user interacts with a malicious file. Simply selecting or right-clicking a file could trigger a remote connection, allowing an attacker to capture NTLM hashes for cracking or pass-the-hash attacks.   Potential for attackers to authenticate as the user, leading to unauthorized access. 

Source:  Microsoft       

In addition to the actively exploited vulnerabilities, several other critical flaws were also addressed: 

  • CVE-2025-21376: A Windows Lightweight Directory Access Protocol (LDAP) RCE vulnerability that could allow attackers to execute arbitrary code remotely. 
  • CVE-2025-21379: A DHCP Client Service RCE vulnerability that may enable remote attackers to execute code with elevated privileges. 
  • CVE-2025-21381: An RCE vulnerability in Microsoft Excel that could be triggered through malicious spreadsheet files. 

Remediation: 

  • Apply Updates: Immediately install the February 2025 Patch Tuesday updates to address these vulnerabilities. 

Conclusion: 

The February 2025 Patch Tuesday release addresses critical security vulnerabilities, including actively exploited zero-days. Timely application of these updates is essential to protect systems from potential threats. Organizations should review the affected products and implement the necessary patches and mitigations to maintain security integrity. 

The attack vector is local, meaning the attacker needs local access — physically or remotely, using SSH method without user interaction and if successful in exploiting, can give the attacker system privileges.

References: 

Security Advisory

Zero-Day Vulnerability in Microsoft Sysinternals Tools  

Summary 

A critical 0-Day vulnerability has been identified in nearly all Microsoft Sysinternals tools, allowing attackers to exploit DLL injection techniques to execute arbitrary code. This presents a significant risk to IT administrators and developers who rely on these utilities for system analysis and troubleshooting.

OEM Microsoft 
Severity High 
Date of Announcement 2025-02-05 
CVEs Not Yet Assigned 
Exploited in Wild No 
Patch/Remediation Available No 
Advisory Version 1.0 
Vulnerability Name Zero-Day  

Overview 

Despite being reported to Microsoft over 90 days ago, the vulnerability remains unpatched, as Microsoft considers it a “defense-in-depth” issue rather than a critical security flaw. 

Vulnerability Name CVE ID Product Affected Severity Impact 
            zero-day  Not Yet Assigned Microsoft Sysinternals Tools (Process Explorer, Autoruns, Bginfo, and potentially others)          High Arbitrary Code Execution, Privilege Escalation, Malware Deployment 

Technical Summary 

The vulnerability is caused by improper handling of DLL loading paths in affected Sysinternals utilities. When these tools search for required DLLs, they follow a specific search order, which may include untrusted locations such as network shares or user-writable directories. 

The issue arises from how Sysinternals tools prioritize DLL search paths, favoring untrusted directories such as: 

  • The Current Working Directory (CWD) 
  • Network locations (e.g., shared drives) 
  • User-writable paths over secure system directories 

This flaw allows attackers to place a malicious DLL in the same directory as a Sysinternals executable, tricking the application into loading the rogue DLL instead of the legitimate system DLL. 

Exploit Workflow 

  1. Attacker crafts a malicious DLL (e.g., cryptbase.dll or TextShaping.dll) containing a payload such as a reverse shell, ransomware, or trojan. 
  1. The DLL is placed in the same directory as a vulnerable Sysinternals tool. 
  1. The user unknowingly executes the tool (e.g., Bginfo.exe or procexp.exe) from that directory. 
  1. The malicious DLL is loaded instead of the legitimate system DLL. 
  1. Attackers gains code execution with the privileges of the running process (potentially SYSTEM privileges if run with admin rights). 

Recommendations 

  1. Avoid Running Sysinternals Tools from Network Locations 
  • Always copy tools to a local trusted directory before execution. 
  • Disable execution of .exe files from network drives if feasible. 
  1. Restrict DLL Search Paths 
  • Use SafeDLLSearchMode to prioritize secure directories. 
  • Implement DLL redirection to force tools to load DLLs from trusted paths. 
  1. Implement Application Control Policies 
  • Use AppLocker or Windows Defender Application Control (WDAC) to block unauthorized DLLs from loading. 
  • Restrict execution of Sysinternals tools to trusted admin-only directories. 
  1. Verify DLL Integrity Before Execution 
  • Use SigCheck (Sysinternals) to ensure all loaded DLLs are digitally signed. 
  • Block execution of unsigned or suspicious DLLs in sensitive directories. 
  1. Monitor for Suspicious DLL Loading Behavior 
  • Enable Sysmon logging to detect anomalous DLL loads (Event ID 7). 
  • Monitor for executions of Sysinternals tools from network shares (Event ID 4688). 

Conclusion 

Despite being responsibly disclosed to Microsoft in October 2024, the vulnerability in Sysinternals tools remains unpatched as of February 2025. Microsoft classifies it as a “defense-in-depth” issue, dismissing it as non-critical, while security researchers highlight its severe impact on enterprises, especially those running tools from network shares. This leaves users reliant on manual mitigations to avoid exploitation.

The Sysinternals tools, developed by Microsoft, are a widely-utilized suite of utilities designed to provide in-depth insights into the processes, services, and configurations of Windows systems. 

References: 

Security Advisory

Critical Security Updates: Microsoft Jan 2025 Patch Tuesday Fixes 8 Zero-Days & 159 Vulnerabilities 

Summary 

Microsoft has released its January 2025 Patch Tuesday updates, delivering critical fixes. Key products impacted include Windows Telephony Service, Windows Digital Media, and MSMQ, among others.

Key take away:

  • Microsoft addressed 159 vulnerabilities across multiple products, including eight zero-day flaws, with three actively exploited in the January 2025 Patch Tuesday updates.
  • Key vulnerabilities include privilege escalation flaws in Hyper-V and remote code execution bugs in Microsoft Excel.
  • This marks highest number of fixes in a single month since at least 2017.
OEM Microsoft 
Severity Critical 
Date of Announcement 2025-01-14 
No. of Vulnerabilities Patched 159 
Actively Exploited yes 
Exploited in Wild Yes 
Advisory Version 1.0 

Overview 

Critical updates were issued for Windows Hyper-V, Windows Themes, Microsoft Access, and Windows App Package Installer. The vulnerabilities include elevation of privilege, remote code execution, and spoofing attacks, impacting various systems. The patch targets a range of critical issues across Microsoft products, categorized as follows: 

  • 58 Remote Code Execution (RCE) Vulnerabilities 
  • 40 Elevation of Privilege (EoP) Vulnerabilities 
  • 22 Information Disclosure Vulnerabilities 
  • 20 Denial of Service (DoS) Vulnerabilities 
  • 14 Security Feature Bypass 
  • 5 Spoofing Vulnerabilities 

The highlighted vulnerabilities include 8 zero-day flaws, 3 of which are currently being actively exploited. 

Vulnerability Name CVE ID Product Affected Severity CVSS Score 
Elevation of privilege vulnerability  CVE-2025-21333,  CVE-2025-21334,  CVE-2025-21335 Windows High 7.8 
Elevation of Privilege Vulnerability CVE-2025-21275 Windows High 7.8 
Remote Code Execution Vulnerability CVE-2025-21186,CVE-2025-21366, CVE-2025-21395 Windows High 7.8 
Spoofing Vulnerability CVE-2025-21308 Windows Medium 6.5 

Technical Summary 

CVE ID System Affected Vulnerability Details Impact 
 CVE-2025-21333,  CVE-2025-21334,  CVE-2025-21335  Windows Hyper-V NT Kernel No information has been released on how elevation of privilege vulnerabilities in Windows Hyper-V NT Kernel Integration VSP, which allow attackers to gain SYSTEM privileges, were exploited in attacks, as they were disclosed anonymously.    Allow attackers to gain SYSTEM privileges 
  CVE-2025-21275  Windows App Package Installer Elevation of privilege vulnerability in the Windows App Package Installer, potentially leading to SYSTEM privileges.   Attackers could gain SYSTEM privileges 
 CVE-2025-21186,CVE-2025-21366, CVE-2025-21395   Microsoft Access  Remote code execution vulnerabilities in Microsoft Access, exploitable via specially crafted Access documents.   Remote Code Execution 
 CVE-2025-21308   Windows Themes Spoofing vulnerability in Windows Themes; viewing a specially crafted theme file in Windows Explorer can lead to NTLM credential theft.   NTLM credential theft 

Source:  Microsoft       

Additional Critical Patches Address High-Severity Vulnerabilities 

  • Eight of this month’s patches address Virtual Secure Mode components, requiring administrators to follow Microsoft’s guidance for updating virtualization-based security (VBS) issues. (CVE-2025-21280, CVE-2025-21284, CVE-2025-21299, CVE-2025-21321, CVE-2025-21331, CVE-2025-21336, CVE-2025-21340, CVE-2025-21370). 
  • Windows NTLM V1 Elevation of Privilege Vulnerability (CVE-2025-21311). 
  • Windows OLE Remote Code Execution Vulnerability (CVE-2025-21298). 

Remediation: 

  • Apply Updates: Immediately install the January 2025 Patch Tuesday updates to address these vulnerabilities. 
  • Disable NTLM: For CVE-2025-21308, consider disabling NTLM or enabling the “Restrict NTLM: Outgoing NTLM traffic to remote servers” policy to mitigate the risk.  
  • Exercise Caution with Untrusted Files: Avoid opening or interacting with files from untrusted sources, especially those with extensions associated with Microsoft Access. 

Conclusion: 

The January 2025 Patch Tuesday release addresses critical vulnerabilities that could allow attackers to gain elevated privileges, execute arbitrary code, or steal credentials. Prompt application of these updates is essential to maintain system security. Additionally, implementing recommended mitigations, such as disabling NTLM, can provide further protection against potential exploits. 

References: 

https://msrc.microsoft.com/update-guide/releaseNote/2025-Jan

Security Advisory

Critical Windows Privilege Escalation Vulnerability with Public Exploit

Cybersecurity researchers reported a critical Windows privilege escalation vulnerability, identified as CVE-2024-43641 affecting Microsoft Windows. This flaw, which affects various editions of Windows Server 2025, Windows 10, and Windows 11, has been assigned a CVSS v3.1 score of 7.8, indicating high severity.

Summary 

OEM Microsoft 
Severity High 
CVSS 7.8 
CVEs CVE-2024-43641 
Exploited in Wild No 
Patch/Remediation Available Yes 
Advisory Version 1.0 

Overview 

A significant Windows Registry Elevation of Privilege vulnerability, identified as CVE-2024-43641, affects multiple editions of Windows. A recently released Proof-of-Concept (PoC) exploit demonstrates how attackers can exploit this flaw to gain elevated privileges. 

Vulnerability Name CVE ID Product Affected Severity 
Windows Registry Elevation of Privilege Vulnerability  CVE-2024-43641  Windows    High 

Technical Summary 

The vulnerability, CVE-2024-43641, exploits a design flaw in Windows registry hive memory management, specifically during a double-fetch process under memory pressure. This flaw allows malicious SMB servers to respond with differing data for consecutive read requests, breaking kernel assumptions and enabling privilege escalation to SYSTEM level. Key technical details are as follows: 

CVE ID System Affected Vulnerability Details Impact 
CVE-2024-43641 Windows 10, Windows 11, Windows Server 2008–2025 The vulnerability involves improper handling of registry hive memory management under memory pressure. A malicious SMB server can respond with differing data to consecutive read requests, breaking kernel assumptions. Exploitation leverages a “False File Immutability” (FFI) condition. Allows attackers to escalate privileges, execute arbitrary code, and compromise system integrity. 

Remediation: 

  • Apply Patches: Users and system administrators are strongly advised to promptly apply the latest security updates. 
  • Monitor Activity: 
  • Monitor logs for suspicious activity related to registry operations. 
  • The cybersecurity community is actively monitoring the situation for any indications of active exploitation in the wild. 

Conclusion: 

CVE-2024-43641 is a high-severity vulnerability with a publicly available PoC exploit. It is crucial to apply security patches immediately and follow best practices to mitigate the risk of exploitation. Organizations must stay alert and monitor ongoing developments to ensure complete protection against this emerging threat. 

References: 

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