June Patch Tuesday 2025: Critical Windows Vulnerabilities, Zero-Days & Remote Exploits

As security professionals and IT administrators worldwide keep a vigilant eye on Microsoft’s monthly security rollouts, this June’s Patch Tuesday offers both relief and renewed resolve. While the patching workload is characterized as relatively mild compared to previous months, critical security issues including a newly patched zero-day highlight the perpetual arms race between software developers and cybercriminals. Let’s dive into what’s new this month, analyze the risks, and uncover what every Windows admin needs to know now to stay ahead.

June’s Patch Tuesday at a Glance​

Microsoft’s June Patch Tuesday addressed a total of 66 vulnerabilities across its portfolio, including Windows operating systems and the Microsoft Office suite. Of these, nine were categorized as critical, while the remainder were labeled important—a classification that, while technically less severe, should not be underestimated in enterprise and high-security environments.
What stands out this cycle is the patch for a notably dangerous zero-day vulnerability actively exploited in the wild: CVE-2025-33053, residing in the Web Distributed Authoring and Versioning (WebDAV) component of Windows. IT defenders must also contend with several critical Office vulnerabilities, and a significant—though currently unpatched—Active Directory design flaw known as “BadSuccessor.” Coupled with a publicly disclosed Server Message Block (SMB) vulnerability, June’s patches underscore both steady improvements and ongoing challenges in Microsoft’s ecosystem.

Key Figures​

Category	Number Patched
Total Microsoft vulnerabilities addressed	66
Non-Microsoft CVEs patched	3
Vulnerabilities rated Critical	9
Remaining vulnerabilities rated Important	57
Office-specific CVEs	~25%

Breaking Down the Windows Zero-Day: CVE-2025-33053​

At the heart of this month’s update is CVE-2025-33053, a WebDAV remote code execution (RCE) vulnerability. Rated “important” on Microsoft’s official scale with a CVSS score of 8.8, this bug has had an outsized impact owing to its active exploitation status.

What Makes CVE-2025-33053 Dangerous?​

• Attack Vector: User interaction (such as clicking a malicious link), common in phishing campaigns.
• Impact: Enables remote attackers to execute malware on the victim’s network—potentially devastating for organizations with exposed WebDAV endpoints or insufficient email filtering.
• Affected Platforms: Windows Server and client operating systems, making the attack surface broad.
• Remediation: For modern, supported Windows versions, a single cumulative update is sufficient. However, legacy environments leveraging security-only updates must also deploy an Internet Explorer (IE) patch to fully address related defects within the MSHTML platform and scripting engine.

Prominent security experts, including Chris Goettl of Ivanti, were quick to highlight that, while officially rated “important,” risk-based analysis should elevate CVE-2025-33053 to “critical” because of its active exploitation. This aligns with widely accepted cyber risk prioritization strategies, where exploitability and business impact often trump mere technical severity ratings.

User Interaction: A Double-Edged Sword​

Unlike some “wormable” vulnerabilities, this flaw does require user interaction. That raises a perennial issue in enterprise security: technical controls must be complemented by well-informed users and layered defenses, as even the best patch can’t stop a click that launches malware after the fact.

SMB Vulnerability: CVE-2025-33073​

Parallel to the WebDAV bug, Microsoft also shipped a fix for a high-severity vulnerability in the Windows Server Message Block (SMB) client (CVE-2025-33073). This flaw is equally weighted at a CVSS 8.8 and presents a valuable opportunity for lateral movement or privilege escalation inside compromised networks.

• Attack Vector: No user interaction needed; exploitation involves coercing a victim machine to connect via SMB to an attacker’s system, potentially using specially crafted scripts or man-in-the-middle techniques.
• Impact: Allows an authenticated attacker to elevate privileges over network resources to SYSTEM level. This privilege elevation could be used with other vulnerabilities for full domain compromise.
• Affected Systems: Broadly impacts supported Windows OS variants, especially in environments with legacy SMB configurations or less restrictive internal network policies.

Microsoft’s advisory describes how an attacker could leverage both technical knowledge and a weak point in SMB authentication to gain the upper hand in what would typically be a highly secure environment. The recommendation is clear: patch immediately and audit any SMB exposures—especially those enabling access from devices not actively managed by central IT.

Microsoft Office: SharePoint and Office Suite Vulnerabilities​

While the majority of this month’s vulnerabilities reside in the Windows OS, administrators mustn’t overlook a flurry of critical updates targeting Microsoft Office and, in particular, SharePoint Server.

SharePoint Server Critical RCEs​

Patches were released for three remote-code execution bugs in SharePoint Server: CVE-2025-47163, CVE-2025-47166, and CVE-2025-47172.

• Severity: All three carry a CVSS rating of 8.8. However, CVE-2025-47172 is considered critical, likely due to a straightforward exploitation technique via SQL injection, as opposed to its “important” siblings.
• Exploit Mechanism: Permits authorized (but malicious) users to execute arbitrary code on the server. In the context of enterprise environments where SharePoint underpins sensitive collaboration workflows, such a flaw could mean substantial risk.
• Mitigation Timeline: A prompt rollout is essential, especially in organizations leveraging SharePoint for document storage and workflow automation.

Remote Code Execution Vulnerabilities in Office​

The revisions also cover four critically-rated RCE flaws (CVE-2025-47162, CVE-2025-47164, CVE-2025-47167, and CVE-2025-47953) in Microsoft Office applications:

• Attack Surface: None of these require user interaction. Attacks may be launched via the document preview pane—a notorious vector for credential phishing and malware distribution.
• Remediation: Immediate deployment of patches is vital, as attackers regularly target Office components as gateways into enterprise environments.
• Critical Analysis: The pattern of vulnerabilities leveraging preview panes recurs frequently, reinforcing the need for technical safeguards that restrict preview capabilities for incoming files, alongside timely patching.

The “BadSuccessor” Dilemma: A Looming Threat in Windows Server 2025​

Despite the significant progress marked by June’s security rollouts, Microsoft’s omission of a fix for a design-level flaw in Windows Server 2025’s delegated Managed Service Accounts (dMSAs) feature is a source of mounting anxiety. Dubbed “BadSuccessor” by Akamai researchers, the vulnerability showcases the risks inherent in adopting powerful automation technologies without comprehensive threat modeling.

What is BadSuccessor?​

• Feature in Focus: dMSAs automate password rotation for service accounts and use Windows Defender Credential Guard for enhanced protection.
• Researcher Insights: Akamai’s Yuval Gordon surfaced a flaw where an attacker with minimal, benign permissions on any organizational unit (OU) could gain control over any security principal within an Active Directory domain.
• Potential Impact: If this flaw becomes widely exploited, attackers could escalate from fringe permissions to full domain administrator—a worst-case scenario in enterprise identity management.
• Disclosure Timeline: Microsoft was notified on April 1 and has acknowledged the issue, but has yet to release a patch or assign a CVE.

Security product leaders, including Ivanti’s Goettl, urge a balanced approach: while the flaw is currently “overhyped” (given prerequisites for exploitation), it holds the seeds of a future major compromise if not addressed. For now, Microsoft customers are urged to strengthen layered defenses, monitor for unusual activity in domain controller logs, and proactively review OU permissions.

Critical Analysis: Strengths and Risks​

Notable Improvements This Month​

• Prompt Attention to Actively Exploited Flaws: The rapid patching of CVE-2025-33053 demonstrates Microsoft’s ongoing commitment to mitigating real-world attacks.
• Breadth of Coverage: Addressing vulnerabilities across the Windows OS, Office Suite, and critical back-end components like SharePoint underscores a holistic approach to shrinking the threat surface.
• Clear Vendor Guidance: For most patched issues, Microsoft offers detailed advisories and frequently asked questions (FAQs) that help customers triage and contextualize risk.

Persistent Pain Points​

• Reliance on User Awareness: Some vulnerabilities, particularly those requiring user interaction, highlight the limits of patching alone. Frequent training and simulated phishing exercises remain essential.
• Legacy and Security-Only Update Gaps: The need for multiple update packages (OS plus IE) in older environments increases operational complexity and the risk of incomplete remediation—an area where automation tools are urgently needed.
• Preview Pane Exploits: The repeated use of Office document preview panes as an attack vector points to the need for architectural changes in file-handling components, not just patches.
• Delayed Response for Active Directory Flaws: The lack of an immediate fix—or even a CVE designation—for issues like BadSuccessor can leave defenders in limbo, underscoring the tension between security disclosure protocols and practical defense.

Potential Risks and Recommendations​

• Active Exploitation Risk: June’s zero-day (CVE-2025-33053) is already weaponized. Patch deployment should be prioritized, and organizations must review firewall, proxy, and WebDAV configurations.
• Insider Threats: Bugs like CVE-2025-47172 (SharePoint, SQL Injection) and the BadSuccessor design issue reinforce that security isn’t just an external game—internal actors or compromised credentials pose profound risks.
• Patch Management Overhead: For firms running older, unsupported, or niche configurations, June’s combination of cumulative and stand-alone patches may increase the risk of misconfiguration or missed updates.
• SaaS and Hybrid Workflows: Office vulnerabilities, particularly those involving preview panes, have cascading implications for organizations dependent on hybrid and cloud-based collaboration tools. Threat modeling should explicitly account for scenario-based attacks via document sharing.

Actionable Steps for Windows Admins​

• Prioritize Zero-Day and Privilege Escalation Patches: Deploy updates for CVE-2025-33053 (WebDAV), CVE-2025-33073 (SMB), and all critical Office RCEs.
• Audit and Restrict Risky Features: Examine the use of WebDAV, SMB, and SharePoint permissions; where possible, restrict functionality and employ network segmentation.
• Review Legacy Update Procedures: If relying on security-only patching (rather than cumulative rollups), double-check that all required packages—including IE updates—are applied.
• Enhance User Awareness: Roll out fresh security training focused on phishing and risky links, especially for executive and frontline users most likely to be targeted.
• Monitor for “BadSuccessor” Exposure: Pending an official patch, restrict dMSA deployment in production and audit for excessively permissive OU configurations. Watch for unusual domain controller activities.
• Restrict Office Preview Pane Features: Limit preview pane usage in Outlook and other Office apps, where feasible, through group policy or endpoint management tools.
• Maintain Defense in Depth: Continue layering technical controls—endpoint detection and response (EDR), application whitelisting, and network anomaly monitoring—to compensate for patch gaps and zero-day risks.

The Road Ahead: Continuous Vigilance​

June’s Patch Tuesday again illustrates that the battle for Windows security is neither solely technical nor entirely administrative—it is an ongoing dance between mitigation and adaptation. With attackers routinely shifting their tactics and targeting both technical and human vulnerabilities, there is no such thing as a passive defense posture.
Microsoft’s swift patching of the WebDAV zero-day and other critical flaws highlights notable progress. Yet, known exposure areas, such as legacy update mechanisms and advanced Active Directory features, remind us that every technical advance comes with the potential for new gaps and oversights.
In summary, Windows administrators who promptly apply patches, tailor risk mitigations to their unique environments, and sustain organization-wide vigilance will fare best against June’s evolving threat landscape. Meanwhile, the industry watches closely to see how long unaddressed flaws like BadSuccessor remain theoretical—before becoming tomorrow’s headline breach.
As always, the key is moving faster than the adversary: patch, segment, train, and monitor. The June Patch Tuesday reveals both how far we’ve come—and how much work remains. For those on the front lines of Windows security, the message is clear: diligence is not optional, and the stakes, as ever, remain high.

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Source: TechTarget June Patch Tuesday resolves Windows zero-day | TechTarget