June Patch Tuesday 2025: Critical Updates, Exploits & Best Practices for Windows Security

Every IT administrator and Windows enthusiast marks the second Tuesday of each month with both anticipation and anxiety: Patch Tuesday remains a critical milestone in maintaining system security and integrity across millions of machines worldwide. This month’s release, however, is notable for its breadth, criticality, and the palpable presence of in-the-wild exploits, making it one of the most consequential updates in recent memory.

An Unusually Hefty Patch Tuesday: The Numbers Tell the Story​

Microsoft’s June Patch Tuesday delivered 67 patches spanning 12 product families, addressing vulnerabilities in platforms as diverse as classic Windows client and server editions, Microsoft 365 (Office, Word, Excel, PowerPoint, Outlook), SharePoint, and even third-party solutions like the Nuance Digital Engagement Platform. Of these, ten vulnerabilities are rated Critical, a heftier share than usual, and 17 scored at least 8.0 on the CVSS base score scale—underscoring the severity and exploitability of these flaws.
To put these statistics in context, the rise in critical vulnerabilities compared year-over-year is both sobering and instructive. In the first half of 2024, only nine critical remote code execution (RCE) vulnerabilities were reported. This year, that figure jumped to 40—a staggering increase pointing not just to better detection and reporting, but also to a technologically complex and increasingly hostile threat landscape. Information disclosure CVEs have likewise ballooned, with 77 so far in 2025 compared to 44 in the same period last year. Denial-of-service CVEs rose from 34 to 57 during the same timeframe.

Patch Distribution by Product​

Here’s how the patch distribution breaks down by product, showing where Microsoft is currently focusing its remediation efforts:

Product Family	Number of CVEs
Windows (including SDK & Security)	45
365	15
Office (excluding overlap with 365)	14
SharePoint	5
Visual Studio	2
Word	2
.NET	1
Excel	1
Microsoft AutoUpdate (Mac)	1
Nuance Digital Engagement Platform	1
Outlook	1
PowerPoint	1

Note: Some CVEs affect more than one product family, so counts by family will exceed the total number of CVEs.

Hallmarks of This Release: What Demands Attention?​

Among the multitude of patches, several specific vulnerabilities stand out for their real-world impact, exploitation profile, or criticality.

CVE-2025-33053: WEBDAV (Web Distributed Authoring and Versioning) RCE—Exploit in the Wild​

The most urgent patch is for CVE-2025-33053, an Important-severity remote code execution vulnerability in the WebDAV component. This vulnerability is being actively exploited and requires immediate remediation. Because it touches legacy components (MSHTML, EdgeHTML, and associated scripting platforms), patching is not always straightforward, especially for customers relying on Security Only updates. These users must supplement their security routine with the IE Cumulative updates to achieve full coverage—a nuance easily missed but critical for maintaining defense in depth.

Exploitation Technique and Mitigation​

Attackers are using increasingly clever methods to bypass traditional endpoint protection—delivering payloads that remain encrypted until in-memory execution, thus skirting both static and AI-based checks. Once decrypted and loaded entirely in memory, traditional disk-based detection fails. Security vendors like Sophos have responded by introducing Dynamic Shellcode Protection, limiting the executable memory allocation per process and thereby thwarting “fileless” attacks. Still, the presence of this bug in active exploit chains highlights the persistent cat-and-mouse game between attackers and defenders.

CVE-2025-33073: SMB Client Elevation of Privilege (Public Disclosure)​

Though not known to be actively exploited, this SMB client vulnerability is the only one this month to be publicly disclosed prior to patching, increasing its risk profile. It affects all supported Windows client and server versions and arises from improper access controls, laying the groundwork for privilege escalation should an attacker gain sufficient foothold. Microsoft's assessment is that it is less likely to see widespread exploitation in the first 30 days, but public disclosure always raises urgency for timely patching.

CVE-2025-47166: SharePoint RCE​

Another notable patch addresses a remote code execution flaw in Microsoft SharePoint Server. This area remains a perennial favorite for targeted attacks, notably in enterprise contexts where SharePoint’s sprawl can introduce significant lateral movement opportunities for a sophisticated adversary.

CVE-2025-32711: M365 Copilot Information Disclosure​

Security researchers uncovered a command-injection vulnerability in M365 Copilot, Microsoft’s high-profile AI-powered productivity tool. This bug, patched in an out-of-band advisory the day after Patch Tuesday, boasted a towering 9.3 CVSS base score and made unauthorized information disclosure feasible through command injection. Microsoft credits responsible disclosure and rapid remediation for curtailing any reported exploitation, but the incident serves as a reminder: the addition of AI and automation to enterprise platforms broadens the attack surface in new and unpredictable ways.

Risk Analysis: Understanding Exploitability and Patch Prioritization​

Every Patch Tuesday, organizations must sift through the deluge of CVEs and triage their remediation efforts. Not all vulnerabilities are created equal: some are already being exploited, while others are expected to become attack vectors soon. According to Microsoft’s threat intelligence, nine additional vulnerabilities this month—besides the WEBDAV flaw—are “more likely to be exploited in the next 30 days.” Among these, several Office flaws are especially concerning due to their preview pane exploitability: simply viewing a malicious document could trigger remote code execution.

Summary Table: June 2025 High-Risk Vulnerabilities​

CVE	Severity	Impact	Exploitation Status
CVE-2025-33053	Important	RCE (WEBDAV)	Actively exploited
CVE-2025-33073	Important	EOP (SMB)	Publicly disclosed, not yet exploited
CVE-2025-47166	Critical	RCE (SharePoint)	High risk
CVE-2025-32711	Critical	Info Disclosure (Copilot)	Patched via advisory
CVE-2025-32713/14/17, CVE-2025-33070/71, CVE-2025-47162/64/67, CVE-2025-47962	Varies	RCE or EOP	Considered more likely to be exploited soon

RCE = Remote Code Execution; EOP = Elevation of Privilege

Patch Quality and Third-party Coordination​

Another feature of this release is the inclusion of ten Adobe Reader patches (four critical) and advisories for Chromium-based Microsoft Edge. These highlight the increasingly interconnected nature of the Windows ecosystem: vulnerabilities in ubiquitous third-party plugins (like Adobe’s PDF stack) or the browser stack can be chained with operating system flaws for devastating effect.
Servicing Stack Updates (SSUs) also feature prominently, reinforcing best practices in Windows update hygiene—without the latest SSUs, cumulative updates may not install or may leave some vulnerabilities unpatched.

The Windows Server Perspective​

Administrators running any of the nine supported Windows Server versions (2008 through 2025) face a complex matrix of exposures. This month, all platforms are affected to greater or lesser degrees—with critical vulnerabilities not limited to the latest releases. Older platforms, especially those out of mainstream support, require special scrutiny: Microsoft's support matrices and advisories must be consulted to ensure complete coverage, especially where server roles (DNS, DHCP, LSASS, etc.) are in play.

Critical Analysis: Strengths and Ongoing Challenges​

Strengths​

• Breadth and Speed of Remediation: Microsoft’s engineering team continues to close vulnerabilities across a dizzying array of platforms, often before public exploitation is reported. The coordinated disclosure and fast turnaround for issues like Copilot’s information leak underscore this.
• Granular Patch Guidance: For each product family and version, administrators can access detailed guidance and knowledge base articles, reducing confusion during remediation.
• Third-party Integration: The close coordination with Adobe and the Chromium project ensures the wider Windows ecosystem benefits from both Microsoft’s telemetry and the expertise of leading security research teams.

Persistent and Emerging Risks​

• Legacy Component Vulnerabilities: The WEBDAV RCE (CVE-2025-33053) highlights the risks of “long tail” software—technology so entrenched it's hard to retire, yet often a ticking time bomb for the unwary. That MSHTML and EdgeHTML are still supported, and remain a target, is both testament to backwards compatibility and a clear attack vector.
• Attack Sophistication: The rapid evolution of exploit techniques—fileless malware, in-memory payloads, triple-stage decryption—demands constant innovation from security vendors and defenders. Traditional antivirus signatures or static scanning alone are nowhere near sufficient.
• Patch Fatigue and Complexity: With 67 updates this month and often overlapping coverage across products, organizations may struggle with deployment strategy. Rushed or uncoordinated patches can inadvertently disrupt workflows.
• Public Disclosure Timeline: The gap between public disclosure and patch application (even if small) represents a window of heightened risk, particularly for widely used components like SMB.

Practical Recommendations for IT Administrators​

• Prioritize Exploited and High CVSS Vulnerabilities: Begin with CVE-2025-33053 (WEBDAV exploit), then move to those marked more likely to be exploited—especially in Office and SharePoint.
• Update Servicing Stacks First: Ensure the latest SSUs are installed before cumulative updates.
• Patch Third-party Tools Alongside Windows: Don’t ignore Adobe Reader and Edge advisories. Attackers love the “chinky armor” provided by neglected plugins.
• Leverage Advanced Protections: Employ endpoint detection and response (EDR) and dynamic protection features, such as Sophos’ Dynamic Shellcode Protection, to catch in-memory and fileless attacks missed by legacy antivirus.
• Audit Server and Role-specific Exposure: Use the detailed Microsoft tables to identify server roles most exposed and test updates in isolated environments before broad deployment.
• Monitor for Public Exploit Code: For any vulnerabilities that have had proof-of-concept or technical details publicly disclosed (like CVE-2025-33073), increase internal monitoring and network segmentation to mitigate “zero-day minus one” risk.
• Educate End-users: Many of this month’s Office vulnerabilities can be triggered merely by previewing a document. Training to recognize suspicious content—coupled with email and document filtering—adds an additional defense.

Looking Ahead: Security Is a Shared Responsibility​

As the first half of the year concludes, the takeaway from the June Patch Tuesday update is unmistakable: the volume, severity, and sophistication of threats facing Windows ecosystems, from desktops to complex server farms, continue to escalate. Patching is necessary but not sufficient; defense in depth remains essential, as does proactive telemetry, rapid user education, and an evolving toolset capable of addressing threats that increasingly target the “gray areas” between endpoint and network.
Administrators who take a risk-focused approach—prioritizing vulnerabilities by likelihood of exploitation and business criticality—will fare best. Yet, as Microsoft’s update cadence and the sheer number of critical flaws show, “security as an afterthought” is no longer tenable.
Every Patch Tuesday is now less of a routine and more of a strategic imperative—one that demands both speed and precision, vigilance and adaptability. This month’s release is a reminder that in cyberspace, the only constant is change, and the only sure defense is a culture of continuous, data-driven improvement.

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Source: Sophos News June Patch Tuesday digs into 67 bugs