The March patch Tuesday looks like a fairly light affair, with only 51 vulnerabilities total and only six rated as critical. However, this patch Tuesday also includes six patches for already exploited, aka "0-Day" vulnerabilities. None of the already exploited vulnerabilities are rated as critical. 

Today's most interesting vulnerability is a not-yet exploited critical vulnerability (CVE-2025-24064) that affects the Windows Domain Name Service. A remote code attacker would exploit this vulnerability by sending a "perfectly timed" dynamic DNS update message. Many Windows DNS servers support dynamic updates, making assigning hostnames to internal IP addresses easier. It is unclear if the server is exploitable if dynamic updates are disabled.

Three of the exploited vulnerabilities affect the NTFS file system. One may lead to remote code execution. The other two are considered privilege escalation vulnerabilities. The remote code execution vulnerability, CVE-2025-24993, is due to a heap-based buffer overflow. Typically, these types of vulnerabilities are exploited when mounting a corrupt file system.

CVE-2025-24985 is related to the Windows Fast FAT File System Driver. Again a heap-based buffer overflow, or "Integer Overflow/Wraparound", the vulnerability allows for remote code execution. The attacker may be remote for both the NTFS and FAT issues, but the attacker will likely upload the corrupt VHD disk image to the victim and mount it locally. Of course, the attacker may just provide the VHD file and trick the victim into mounting it locally.

The two remaining already exploited vulnerabilities affect a security feature bypass in the Microsoft Management Console and a privilege elevation vulnerability in the Win32 kernel subsystem. 

Three of the critical vulnerabilities affect the Windows Remote Desktop Services. Systems are vulnerable if they act as a remote gateway. This is important because gateways are likelier to be exposed to the internet. However, the attacker will also have to win an unspecified race condition, often resulting in less reliable exploits.

The remaining critical vulnerabilities affect Microsoft Office and the Windows subsytem for Linux.

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Johannes B. Ullrich, Ph.D. , Dean of Research, SANS.edu
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