March 2025’s arrival in the world of Microsoft security sees another Patch Tuesday rolling out 57 fresh vulnerabilities. That figure is in line with recent months, but the real story is tucked within the details: Microsoft acknowledges active exploitation for as many as six vulnerabilities, all already flagged in CISA’s Known Exploited Vulnerabilities (KEV) catalog. In addition, one more has been publicly disclosed, raising the stakes for IT departments and Windows users who might otherwise treat these updates as a tick-box exercise.
The headline number—57 vulnerabilities—is far from reassuring, but it’s the qualitative aspects that matter most this month. Microsoft has, for the sixth straight month, published vulnerabilities deemed “zero-day” (known to be exploited before a patch is available) without labeling any as “critical” at the time of disclosure. This no-critical-classification trend may reassure some, but merits close scrutiny; the lack of a critical label does not negate risk, especially when active exploitation is verified.
Additionally, Microsoft revealed six critical remote code execution (RCE) vulnerabilities. Notably, browser flaws—often a separate high-risk class—are not even included in the 57-count for March, as ten such browser vulnerabilities have been marked and patched separately earlier in the month. This separation is standard, yet it queues up a silent threat vector many organizations might inadvertently overlook, given how frequently browsers serve as an entry point for attackers.
Strikingly, Windows 11 and Server 2019 (and later systems) are not listed as vulnerable. This gap invokes a broader question: have architectural changes rendered newer systems immune, or does the security community face undisclosed technical nuances? The Win32 subsystem hasn’t been deprecated, so transparency here would be welcome; users and defenders need to know if their systems are inherently safer or merely excluded for other reasons.
The attack is physically initiated, but successful exploitation can yield privileged information as memory heap chunks are dumped to log files. The CVSSv3 base score of 4.6 might seem low, reflecting the need for direct access and certain conditions to align, but the professional security community knows even the smallest foothold can be enough for a particularly motivated adversary.
Further complicating matters, functional exploit code is circulating—a rare and sobering escalation for a vulnerability with modest theoretical scoring. The vulnerability underlines the importance of physically securing endpoints and maintaining strict controls on removable media—a best practice sometimes disregarded in the era of remote and hybrid work.
While this may seem esoteric, it is, in fact, not. The proliferation of VHD-based workflows for backup, virtualization, and cloud integration means that many environments are now VHD-aware—even if end users might not realize it. Organizations leveraging virtual storage need to revisit user training and, where feasible, shore up defenses against the subtle social engineering that often precedes technical exploitation.
More severe is CVE-2025-24993, hinging on mounting a malicious VHD to trigger a heap-based buffer overflow. The ultimate prize for the attacker is local code execution. The complexity is low, needing only user interaction—the so-called “remote” in this case referring to the attacker’s location, not the mechanism. Microsoft maintains that exploitation requires a user to run code within their own context, but history shows that once a system is compromised, privilege escalation is often only a short step away.
In the end, March 2025 is not so much about a single headline vulnerability but the cumulative, compounding risk inherent in sprawling, complex, and deeply integrated Microsoft environments. The price for ignoring the details is a tab most organizations can ill afford to pay. Patch early, patch often—and never underestimate any vulnerability merely because it is deemed “not critical.” In the relentless arms race of Windows security, context is everything, and complacency is the real enemy.
Source: itbrief.com.au March Patch Tuesday reveals 57 vulnerabilities
The Numbers: Context and Consequences
The headline number—57 vulnerabilities—is far from reassuring, but it’s the qualitative aspects that matter most this month. Microsoft has, for the sixth straight month, published vulnerabilities deemed “zero-day” (known to be exploited before a patch is available) without labeling any as “critical” at the time of disclosure. This no-critical-classification trend may reassure some, but merits close scrutiny; the lack of a critical label does not negate risk, especially when active exploitation is verified.Additionally, Microsoft revealed six critical remote code execution (RCE) vulnerabilities. Notably, browser flaws—often a separate high-risk class—are not even included in the 57-count for March, as ten such browser vulnerabilities have been marked and patched separately earlier in the month. This separation is standard, yet it queues up a silent threat vector many organizations might inadvertently overlook, given how frequently browsers serve as an entry point for attackers.
Kernel Vulnerabilities: Old Products, New Problems
Older Windows systems received a crucial fix this round: CVE-2025-24983. This vulnerability strikes at the Win32 kernel subsystem and is being exploited in the wild. The exploit does not require any user interaction and, once pulled off, grants SYSTEM-level control—the Holy Grail for attackers. The only slight upside is the need for the attacker to succeed in a race condition, which raises the bar for attackers but by no means disqualifies determined or well-resourced adversaries.Strikingly, Windows 11 and Server 2019 (and later systems) are not listed as vulnerable. This gap invokes a broader question: have architectural changes rendered newer systems immune, or does the security community face undisclosed technical nuances? The Win32 subsystem hasn’t been deprecated, so transparency here would be welcome; users and defenders need to know if their systems are inherently safer or merely excluded for other reasons.
The Physically Dangerous: NTFS and USB Weaponization
If defense-in-depth was ever an academic idea, recent months have made its practical necessity vivid. Patch Tuesday’s rollup brings a new twist: the active weaponization of physical access vectors. NTFS, the backbone file system of Windows environments, is at the heart of two zero-day vulnerabilities, notably CVE-2025-24984. This flaw is the stuff of administrator nightmares: the attack leverages a malicious USB drive as its delivery mechanism, exploiting how sensitive information may inadvertently end up in a log file due to CWE-532 (“Insertion of Sensitive Information into Log File”).The attack is physically initiated, but successful exploitation can yield privileged information as memory heap chunks are dumped to log files. The CVSSv3 base score of 4.6 might seem low, reflecting the need for direct access and certain conditions to align, but the professional security community knows even the smallest foothold can be enough for a particularly motivated adversary.
Further complicating matters, functional exploit code is circulating—a rare and sobering escalation for a vulnerability with modest theoretical scoring. The vulnerability underlines the importance of physically securing endpoints and maintaining strict controls on removable media—a best practice sometimes disregarded in the era of remote and hybrid work.
NTFS Strikes Again: Memory and Code Execution
The month’s NTFS vulnerabilities do not stop with information disclosure. CVE-2025-24991 describes an out-of-bounds read again resulting in information disclosure but this time triggered through the mounting of a malicious virtual hard disk (VHD). No clever USB maneuvers here; attackers can simply persuade users to interact with crafted virtual storage.While this may seem esoteric, it is, in fact, not. The proliferation of VHD-based workflows for backup, virtualization, and cloud integration means that many environments are now VHD-aware—even if end users might not realize it. Organizations leveraging virtual storage need to revisit user training and, where feasible, shore up defenses against the subtle social engineering that often precedes technical exploitation.
More severe is CVE-2025-24993, hinging on mounting a malicious VHD to trigger a heap-based buffer overflow. The ultimate prize for the attacker is local code execution. The complexity is low, needing only user interaction—the so-called “remote” in this case referring to the attacker’s location, not the mechanism. Microsoft maintains that exploitation requires a user to run code within their own context, but history shows that once a system is compromised, privilege escalation is often only a short step away.
Fast FAT Driver: An Exploitation Cascade
This month’s NTFS parade almost overshadows another file system driver, Fast FAT, the target of CVE-2025-24985. Like its NTFS cousins, this flaw can be exploited by mounting a malicious VHD, enabling an integer overflow or wraparound—and, once again, Microsoft says the vulnerability is being exploited in the wild. With a set of four related vulnerabilities (CVE-2025-24984, -24991, -24993, and -24985) all attributed to likely the same anonymous researcher or group, defenders must recognize both the technical risk and the organized, methodical probing of Windows file system components by threat actors.Management Console and Security Feature Bypasses
It has been several months since a notable Microsoft Management Console (MMC) vulnerability, but March 2025 reintroduces the vector with CVE-2025-26633. This is a security feature bypass vulnerability (SFB). Publicly available exploit code exists, and exploitation in the wild is confirmed. MMC’s wide latitude in hosting custom management tools means even a seemingly minor SFB can have outsized consequences, potentially enabling attackers to bypass restrictions or elevate privileges via administrative utilities. Although successful exploitation here requires both environmental preparation and user participation (e.g., opening malicious files), the wider IT community should not dismiss MMC vulnerabilities as only niche concerns—their potential for lateral movement and stealth cannot be overstated.Microsoft Access, Use-After-Free, and the Limits of Preview Pane Protection
CVE-2025-26630 affects Microsoft Access—an often-underestimated component lurking in countless business environments. This vulnerability is the classic CWE-416 (Use After Free), with exploitation relying on opening a maliciously crafted file. Microsoft notes that the Preview Pane does not serve as an attack vector, reducing casual drive-by risk. However, reliance on user caution or layered defenses is no substitute for patching. Intriguingly, Unpatched.ai is credited with discovery here—the same team responsible for a series of Access zero-days earlier this year—signaling ongoing interest in legacy components of the Microsoft ecosystem. The risk is more than theoretical; business logic frequently drives macro-laden Access applications, which often end up whitelisted by tired or overworked security teams.WSL2 Arbitrary Code Execution: The Email Factor
Potentially the most worrying (or at least alarming) vulnerability this month is CVE-2025-24084 in the Windows Subsystem for Linux 2 (WSL2) kernel. Microsoft categorizes this as critical, with a CVSSv3 score of 8.4. The standout detail: exploitation could potentially require no user interaction whatsoever—in one scenario, the mere act of receiving a malicious email could trigger the bug. The precise technical conditions are not fully publicized, but the mention of “magic email” vectors echoes the worst-case scenarios that characterized infamous vulnerabilities of the past (such as the classic image-processing bugs). For enterprise defenders, failing to patch is simply not an option.RDP Server: The Lateral Movement Dream
Remote Desktop Protocol (RDP) remains a favorite both for legitimate system administrators and attackers alike. CVE-2025-26645 is a new critical RCE affecting RDP clients. If a user connects to a malicious RDP server, the server can execute code on the client—without any further need for social engineering or exploit chaining. This is the classic lateral movement vector: once inside a network, attackers set up poisoned servers and wait for admins (or automated management tools) to connect. The CVSSv3 score of 8.8, along with a “critical” designation, should serve as a clarion call. Administrators must immediately assess all RDP connections—especially those traversing less-secure environments or VPN jump boxes.Lifecycle News: Legacy Products Marching On
Beyond the immediate security content, Microsoft notes impactful product lifecycle updates: SQL Server 2019 has transitioned from mainstream to extended support, Visual Studio App Center will sunset at the end of March, and Dynamics GP 2015 soon exits extended support entirely. While not direct security vulnerabilities, these lifecycle shifts can have indirect security consequences—unpatched software quickly becomes the weakest link, especially when attackers are keen to target legacy products that organizations are slow to retire.Analysis: Trends, Tensions, and Takeaways
This Patch Tuesday repeats and intensifies core themes seen over the past year of Microsoft security updates:- Active Exploitation Is the New Normal: Each month, multiple vulnerabilities are already being exploited by the time patches are released, reflecting both the responsiveness of Microsoft’s disclosure process and the adversaries’ operational speed. Organizations can no longer assume that patching alone is adequate; they must boost vigilance around log analysis, anomaly detection, and attack surface minimization as well.
- Critical Labels Don’t Reflect True Urgency: Microsoft’s proprietary severity rankings and the CVSS system sometimes give a misleading sense of safety. A vulnerability exploited in the wild should always be a top priority—regardless of whether it is technically labeled “critical.”
- Physical Access Still Matters: The persistence of USB-based and VHD-related exploits is a sobering reminder that even in a cloud-first, remote-work, zero-trust era, physical vectors remain lucrative. Device control policies and endpoint detection solutions must not become secondary concerns.
- Legacy Components Aren’t Going Away: The recurrence of file system driver bugs, Access vulnerabilities, MMC bypasses, and kernel-level escalations should quash any notion that legacy Windows components are irrelevant. For every organization that has fully migrated to Windows 11 or locked down file system access, there are dozens still running outdated systems or maintaining mixed environments with broad attack surfaces.
- Attackers Exploit Social and Technical Weaknesses: Multiple vulnerabilities this month require user interaction—mounting a VHD, opening a file, connecting to a server. That does not diminish their risk—instead, it plays into the success rates of phishing and social engineering, well-established and highly effective attack techniques.
- Acknowledgment Patterns Tell a Story: The repeated credit to a single (anonymous) researcher for the file system driver bugs points to concentrated security research activity on previously neglected system components. Where proactive research leads, both offense and defense follow; defenders should anticipate a continued focus on deep, “below the application layer” Windows vulnerabilities.
Defensive Priorities for March 2025
IT administrators and Windows power users cannot afford to treat March’s Patch Tuesday as business as usual. The presence of exploited-in-the-wild vulnerabilities with both physical and remote exploit vectors, the criticality of RDP and WSL2 bugs, and the ongoing uncovering of file system driver flaws suggest several immediate priorities:- Patch Immediately: Prioritize all systems, but especially those exposed to physical access, using RDP, running WSL2, or leveraging virtualization features involving VHD files.
- Review and Harden RDP Practices: Continue enforcing the principle “never connect to untrusted RDP servers,” isolate admin workstations, and review audit logs for new or suspicious RDP connection attempts.
- Clamp Down on Physical Media: Reassess and re-enforce USB device control. Where feasible, consider systems with full lockdown of removable drives outside audited and authorized use cases.
- Revisit File System Security: Update monitoring for any tampering or unusual log file content, and communicate with users about the risks associated with mounting unfamiliar VHD images.
- Legacy Is Not Low Risk: Any legacy applications, especially Access databases, should be patched or migrated where possible, and closely monitored regardless.
- Train for a Layered Defense: Remind users about the reality of social engineering, and update defensive playbooks for detecting and responding to lateral movement scenarios facilitated by RDP or management console abuse.
Looking Ahead: Security in a Hybrid Reality
March 2025’s vulnerabilities reflect the complex, hybrid reality of today’s enterprise computing:- Windows environments are a patchwork of old and new operating systems, with some organizations quick to adopt Windows 11 and others still relying on Windows 7/8/10 or even Server 2012/2016 editions.
- Attackers target not just the latest and greatest, but the overlooked: file system drivers, management consoles, plug-in mechanisms, legacy scripting and database engines.
- The shape of exploitation continues to evolve: physical and local attack vectors are rising even as ransomware and remote exploitation dominate headlines.
In the end, March 2025 is not so much about a single headline vulnerability but the cumulative, compounding risk inherent in sprawling, complex, and deeply integrated Microsoft environments. The price for ignoring the details is a tab most organizations can ill afford to pay. Patch early, patch often—and never underestimate any vulnerability merely because it is deemed “not critical.” In the relentless arms race of Windows security, context is everything, and complacency is the real enemy.
Source: itbrief.com.au March Patch Tuesday reveals 57 vulnerabilities
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