Microsoft June 2025 Patch Tuesday: Critical Vulnerabilities & Urgent Security Updates

June’s security update rollout by Microsoft has sent ripples across the IT landscape, underlining not just the persistent innovation of attackers but also the relentless burden on organizations and end users to stay one step ahead. This latest patch cycle, landing on June 11, featured an extensive collection of 67 vulnerabilities affecting flagship platforms like Windows, Microsoft Office, Azure, and Visual Studio. The breadth of affected products and the critical nature of several exploits underscore the very real and immediate risks facing both enterprises and everyday users in 2025.

Microsoft’s June Patch Tuesday: A Strategic Response to Evolving Threats​

With digital transformation accelerating, the constant expansion in attack surfaces is matched only by the sophistication of those looking to exploit them. June’s Patch Tuesday is a microcosm of this arms race. Of the 67 vulnerabilities addressed, 11 are classified as critical by Microsoft’s own severity ratings—a notably high count—while 58 fall into the “important” category. These patches arrive amid confirmed, in-the-wild exploitation of a WEBDAV Remote Code Execution vulnerability (CVE-2025-33053), leaving little doubt that immediate patching isn’t just advised, but mandatory.

The Numbers: An Objective Breakdown​

• Total vulnerabilities patched: 67
• Critical vulnerabilities: 11
• Important vulnerabilities: 58
• Publicly exploited (zero-day): CVE-2025-33053 (WEBDAV RCE)

These numbers, confirmed against Microsoft’s official release notes and cross-referenced with independent advisories from NSFOCUS and CERT sources, reflect a significant mid-year escalation in critical flaw disclosure, especially for core Windows components.

Spotlight on Key Vulnerabilities​

The June release is peppered with vulnerabilities that, if left unaddressed, would offer fertile ground for attacks ranging from lateral movement and privilege escalation to direct remote code execution. Below, we unpack several of the most significant, drawing on Microsoft’s updated CVE documentation and independent threat intelligence.

1. Windows Schannel Remote Code Execution (CVE-2025-29828)​

Schannel, the cryptographic provider enabling TLS/SSL protocols in Windows, has been hit with a memory leak bug escalating to remote code execution. This flaw allows an unauthenticated attacker to craft a barrage of malicious ClientHello messages, potentially executing arbitrary code on affected systems. The implications are severe—TLS is foundational for encrypted communications across enterprise and critical infrastructure.

• CVSS score: 8.1
• Exposure: All supported versions of Windows 11 (22H2, 23H2, 24H2) and Windows Server (2022, 2025), including ARM64 variants.

This marks the most serious Schannel RCE since the infamous FREAK attack, and while exploitation complexity is non-trivial, it is plausible in real-world settings, particularly in cloud-hosted or border-exposed environments.

2. Microsoft Word Remote Code Execution (CVE-2025-32717 and CVE-2025-47957)​

The productivity mainstay Word faces two separate RCEs:

• CVE-2025-32717: Heap-based buffer overflow, triggered by opening or previewing crafted RTF files.
• CVE-2025-47957: ‘Use after release’ flaw, enabling code execution during local interactions.

Both vulnerabilities are exploitable by attackers using social engineering tricks—convincing users to open malicious files remains one of the most effective intrusion vectors. Notably, exploitation does not require authentication or elevated permissions, greatly increasing attack feasibility.

• CVSS scores: 8.4
• Affected: Microsoft 365 Apps for Enterprise, Office LTSC 2024/2021 (32/64-bit).

Confirmed by Microsoft’s documentation and outlined in NSFOCUS advisories, enterprise and education sectors should prioritize patch deployment, given heavy institutional dependency on Office.

3. WEBDAV Remote Code Execution (CVE-2025-33053) — Actively Exploited​

The standout threat this cycle, WEBDAV’s mishandling of file paths allows unauthenticated attackers to control file name/path references and subsequently execute code if a user interacts with specially crafted links. With exploitation already detected in the wild, this vulnerability merits immediate response.

• CVSS score: 8.8
• Attack vector: Email phishing, drive-by downloads, malicious intranet sites.
• Affected systems: Broad—spanning Windows Server 2008 through 2025, Windows 10, and all contemporary Windows 11 versions (including ARM64).

Real-world exploitation, as cited by Microsoft and corroborated by threat monitoring communities, presents a compelling case for rapid patch management. The risk is exacerbated in environments with legacy exposure or poor internal segmentation.

4. Windows Routing and Remote Access Service (RRAS) RCE (CVE-2025-33064)​

RRAS again appears as a weak point, this time through a heap overflow bug reachable by unauthenticated remote actors.

• CVSS score: 8.8
• Impact: Code execution on core network routing infrastructure
• Affected: Server installations from 2012 R2 to 2025, plus Windows 10/11 client editions.

Given RRAS’s usage in hybrid cloud and VPN scenarios, the consequences of exploitation could include network pivoting and persistent access, laying the groundwork for follow-on attacks or data exfiltration.

5. Power Automate for Desktop Privilege Escalation (CVE-2025-47966)​

The automation platform’s leakage of sensitive information opens the door to privilege escalation. With an eye-watering CVSS score of 9.8, this is the highest-rated risk in the advisory batch.

• Exploitability: Local attackers obtaining admin privileges via leaked tokens or secrets.
• Enterprise applicability: Power Automate is increasingly common in workflow automation, especially across regulated verticals adopting citizen development.

Organizations relying on Power Automate for critical operations should audit workflows and update agents promptly.

6. Windows Netlogon Privilege Escalation (CVE-2025-33070)​

Netlogon, essential for authentication and domain controller interactions, is again a focal point. The use of uninitialized resources enables attackers to send malicious requests and gain domain admin privileges. Given its similarity to past “Zerologon” style attacks, defenders must treat this with gravity.

• CVSS score: 8.1
• Breadth of impact: Virtually all maintained versions of Windows Server and clients back to Windows 10.

As domain controller security often underpins an enterprise’s broader risk profile, this vulnerability should be handled as a high-urgency item.

Product and Version Matrix​

The following table condenses some of the most critical vulnerabilities, their assigned CVE numbers, and at-risk versions:

Vulnerability	CVE	Affected Products	Severity
Schannel RCE	CVE-2025-29828	Windows 11, Server 2022/2025 (all editions)	Critical
Word RCE (buffer overflow)	CVE-2025-32717	M365 Apps, Office LTSC 2021/2024 (32/64 bit)	Critical
WEBDAV RCE (wild exploitation)	CVE-2025-33053	Windows Server 2008-2025, 10, 11 (all)	Critical
RRAS RCE	CVE-2025-33064	Server 2012-2025, Win10/11	Critical
Power Automate Priv Escalation	CVE-2025-47966	Power Automate for Desktop	Critical
Word RCE (use after release)	CVE-2025-47957	Office LTSC/M365 (32/64 bit)	Important
Netlogon Priv Escalation	CVE-2025-33070	All Windows Server, 10, 11	Critical

Context and Analysis: Why This Patch Cycle Deserves Urgent Attention​

June’s Patch Tuesday is not unique in the number of vulnerabilities, which typically fluctuate between 40 and 100 monthly. However, the confluence of factors sets it apart:

• Diversity of attack vectors: Both client- and server-side flaws, local and remote, authenticated and unauthenticated.
• In-the-wild exploitation: Immediate threats from active campaigns (mainly WEBDAV RCE).
• Core infrastructure impact: Netlogon, Schannel, and RRAS are foundational elements across enterprise and cloud deployments.
• Heightened CVSS ratings: Several bugs rated 8.0+; Power Automate crosses into 9+ territory, denoting almost “perfect conditions” for successful attack.

Strengths in Microsoft’s Security Model​

Microsoft’s transparent vulnerability disclosure and patch release cadence are industry benchmarks. Early public awareness, detailed severity assignments, and comprehensive technical documentation empower IT departments to triage quickly. The company’s integration of telemetry and threat intelligence feeds (leveraged through both Defender and partner CERTs) enables near-real-time detection of exploitation in the wild, justifying urgent out-of-band warnings to customers.
Further, the surface coverage is broad—patches are provided for legacy and current platforms alike, reflecting Microsoft’s continuing commitment to backward compatibility and lifecycle management. For supported versions, Microsoft’s Update Catalog and Windows Update distribution make patch application straightforward and scriptable.

Potential Risks and Unresolved Pain Points​

While the security mechanisms around Patch Tuesday have matured, persistent risks remain, many of which have been called out by independent security researchers and advisory groups:

• Patch Lag and Exposure Window: Even with automations, many organizations—especially those in regulated industries—delay patching for days or weeks while conducting impact assessments. This leaves a critical window for attackers, particularly when proof-of-concept exploits circulate publicly.
• Complex Legacy Environments: Enterprises running extended support or mixed-version fleets face nontrivial challenges with patch coverage. Some older product lines receive only limited or delayed attention, increasing the utility of n-day exploits.
• Social Engineering and User Awareness: Several of the June vulnerabilities (notably Word and WEBDAV RCEs) are exploitable by simply convincing users to interact with malicious content. Technical mitigations only go so far without bolstered user training and downstream controls (e.g., sandboxing, attachment blocking).
• Automation Pipeline Insecurity: The critical flaw in Power Automate is a sharp reminder that low-code/no-code platforms can serve as privileged attack chains. As citizen development expands, defenders must adapt their scanning, monitoring, and least-privilege policies accordingly.
• Patch Validation Failures and Shadow IT: Microsoft’s official documentation repeatedly notes the possibility of failed patch installs due to network or system anomalies. Unpatched endpoints or “shadow IT” scenarios (where assets are not centrally managed or monitored) pose ongoing compliance and security challenges.

Actionable Mitigation: What Users and Admins Should Do​

Microsoft and partners urge all stakeholders to move with speed and caution:

• Immediate patching: Apply June’s security update to all affected systems. Use Windows Update or the Microsoft Update Catalog for explicit package downloads.
• Validation and reporting: Confirm successful update installation by checking update history (Settings → Update & Security → Windows Update). For failed updates, leverage documented workarounds and retry mechanisms.
• Review automation workflows: Organizations using Power Automate should audit their automations for sensitive information leakage and implement least-privilege access.
• Enhance endpoint protections: Consider implementing advanced threat protection, sandboxing, and network segmentation to buffer against exploits in the wild, particularly those relying on user interaction.
• Employee vigilance: Bolster anti-phishing training, especially around opening or previewing Office documents and interacting with unfamiliar links (key for mitigating Word and WEBDAV attacks).

The Bigger Picture: Microsoft’s Security Landscape in 2025​

The June update cycle encapsulates broader trends in cybersecurity:

• Hybrid work, expanded risk: IoT, mobile endpoints, and remote access services (RRAS, Netlogon) increase exploitability.
• Attack sophistication: Memory corruption and logic flaws (Schannel, Word) remain favored by advanced groups, even as low-skill phishing continues to yield returns.
• Cloud and automation: As businesses integrate Power Automate and Azure into daily ops, automation and orchestration become both assets and liabilities.
• Regulatory pressure: Governments and industry groups are mandating ever-faster remediation timelines, raising compliance risk for laggards.

This patch cycle stands as a case study in the importance of layered defenses. Left unaddressed, any one of these major vulnerabilities—especially those confirmed as actively exploited—could catalyze widespread compromise. The security community, in concert with Microsoft, continues to adapt, but as attack surfaces evolve, so must strategies for patch management, detection, and user education.

Conclusion: Vigilance, Speed, and Strategy​

June’s Microsoft security update is a call to action on multiple fronts. From C-suite executives and network admins to home users relying on Office suites, the message is clear: the threat landscape is ever-changing, and complacency is the real vulnerability. The 67 vulnerabilities, particularly the 11 deemed critical, are not just numbers on a dashboard—they represent real-world risk, already leveraged by determined attackers.
Patching, while sometimes fraught with logistical hurdles, remains the single highest-ROI security activity for digital defenders. Coupled with sound policy, user awareness, and investment in detection and response, it is the linchpin of a robust defense-in-depth strategy.
Stay alert, verify patch deployment, cultivate a culture of continuous vigilance, and remember: in cybersecurity, being slightly ahead is infinitely better than being moments too late. For full details and ongoing advisories, consult Microsoft’s official update guide and monitor trusted intelligence feeds for signs of evolving threats.

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This article is based on the latest official sources from Microsoft, independent advisories from NSFOCUS and CERT, and is intended to provide accurate, actionable insight for IT professionals and enthusiasts. Given the fast-moving nature of cybersecurity, readers are encouraged to confirm specifics with vendor documentation and patches at the time of reading.

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Source: Security Boulevard Microsoft’s Security Update in June of High-Risk Vulnerability Notice for Multiple Products