Top 5 High-Risk CVEs of June 2025 & How to Patch with Microsoft Updates

June 2025 brought a wave of dangerously exploitable vulnerabilities—bugs that threaten businesses large and small. From remote code execution to privilege escalation, attackers are already capitalizing on several of these flaws. This post dives into the top 5 high-risk CVEs, explaining what they are, how Microsoft is patching them, and how you can protect your systems now.

Why These CVEs Matter

Each vulnerability below enables attackers to:

1. Execute code remotely
2. Escalate privileges directly to SYSTEM or administrator
3. Exploit core Windows services—including WebDAV, SMB, Schannel, and Office preview panes

These are not theoretical flaws—they are being actively weaponized. Microsoft and security firms have flagged them as “exploit in the wild” or Critical, urging immediate remediation (kocho.co.uk, thezdi.com, learn.microsoft.com).

1. CVE-2025-33053 – WebDAV Remote Code Execution

A serious flaw in Windows’ WebDAV service enables unauthenticated attackers to execute code remotely simply by tricking a user into accessing a malicious URL (reddit.com).

Microsoft Patch:

Included in the June 10, 2025 Windows patch (e.g., KB5060533) covering Windows 10 version 21H2/22H2 (support.microsoft.com).

✅ Recommendation: Deploy this cumulative update immediately across all affected endpoints and servers.

2. CVE-2025-33073 – SMB Client Elevation of Privilege

This SMB client flaw allows local attackers—or attackers tricking a user into connecting to a rogue SMB server—to elevate to SYSTEM privileges. Microsoft lists it as Important with serious impact (qualys.com, thezdi.com).

Microsoft Patch:

Also included in KB5060533 (June 10, 2025) for Windows 10 and Windows Server.

✅ Recommendation: Patch quickly to close off local privilege escalation paths that could lead to full system control.

3. CVE-2025-29828 – Schannel Remote Code Execution

A flaw in Schannel, the Windows encryption layer, can lead to remote code execution without any user interaction—simply through establishing a malicious SSL/TLS connection (thezdi.com).

Microsoft Patch:

Patched via the June 2025 Patch Tuesday; check your Security Update Guide for Schannel fixes in Windows 10/11 and Server platforms.

✅ Recommendation: Apply the relevant cumulative updates immediately to secure communications across servers and endpoints.

4. CVE-2025-47162 (and related) – Office Preview-Pane RCE

Multiple critical Remote Code Execution CVEs in Microsoft Office, including CVE-2025-47162, 47164, and 47167, allow code to run via malicious documents in the Preview Pane—requiring no user clicks (crowdstrike.com, thezdi.com).

Microsoft Patch:

These are covered in Office security updates—look for June 2025 entries in the Microsoft 365 Apps Security Updates page (learn.microsoft.com).

✅ Recommendation: Update all Office versions (2019, 2021, LTSC, Microsoft 365 apps) to patch these preview-pane exploits. Consider temporarily disabling the Preview Pane where risk is highest.

5. CVE-2025-33071 – KPSSVC (KDC Proxy Service) RCE

The Kerberos KDC Proxy Service vulnerability lets attackers send a malicious request and execute code remotely as SYSTEM (thezdi.com).

Microsoft Patch:

Patched in the June cumulative update for Windows hosts that support KPSSVC—mostly relevant for domain-joined Windows 10/11 and Server systems. See updates in KB5060533 and the Security Update Guide.

✅ Recommendation: Apply patches to all domain-joined machines and servers to prevent network-based Kerberos exploitation.

Brief on June Patch Tuesday

On June 10, 2025, Microsoft issued cumulative updates covering 65 CVEs, among them:

• 1 actively exploited zero-day
• 9 Critical CVEs, and
• 56 Important CVEs (tenable.com).

Key risk types included remote code execution (38%), info disclosure (26%), and privilege escalation (20%) (crowdstrike.com).

Action Plan for Administrators

1. Audit your systems: Use WSUS/SCCM, Qualys, or Tenable to identify missing patches, particularly for KB5060533.
2. Prioritize high-risk updates: Focus on CVE-2025-33053, -33073, -29828, -47162, and -33071.
3. Deploy emergency patches: Push updates to servers and endpoints immediately—even out of band where needed.
4. Verify remediation: Confirm installations and test vulnerability resolution.
5. Monitor threat intelligence; watch for post-patch exploitation attempts.

TL;DR

† includes 47164, 47167, 47172, and related Office CVEs.

Final Thoughts & Call to Action

These CVEs aren’t just lines in a report—they're active threats. Imagine an attacker exploiting silently through an employee's preview pane, or hijacking encrypted connections via Schannel. For network defenders, every minute without updates is risk.

Optimize365 offers automatic remediation, helping businesses like yours stay ahead of evolving threats by automating the patching process. With Optimize365, you can streamline security operations, ensuring critical vulnerabilities like these are patched swiftly and accurately.

If you manage IT infrastructure, pause every non-critical task and roll out these patches now. After patching, monitor logs for suspicious activity and validate remediation. For example, Optimize365 can auto-remediate these vulnerabilities, saving time and minimizing the risk of human error.

These vulnerabilities highlight a sobering truth: even core system components—Office, SMB, WebDAV, Schannel—can harbor gateways into our networks. Our defense depends on vigilance and timely action. Optimize365 can further enhance your network defense, ensuring that patches are deployed on time and vulnerabilities are mitigated quickly.

Share this post with your team and urge your peers: patch now, assess impact, and resist threats before systems fall. Don’t wait—act today with Optimize365 for seamless security remediation.

References & Further Reading

• Microsoft Security Update Guide (search "June 2025 Patch Tue")
• Windows update KB5060533 (June 10, 2025 cumulative) – patch details (thezdi.com, learn.microsoft.com, securityboulevard.com, crowdstrike.com)
• Office security updates page (June 2025 release) ()
• Patch Tuesday analysis: RCE (38%), Info‑disclosure (26%), EoP (20%) (crowdstrike.com)
• Kocho & Reddit commentary on WebDAV and SMB outbreaks (kocho.co.uk)

By proactively applying these patches, you're not just closing doors to attackers—you’re defending trust, data integrity, and operational resilience. Don’t wait—act today with Optimize365 for seamless, automated remediation.