Microsoft Patch Tuesday – June 2025 In-depth Analysis
On June 10, 2025, Microsoft released its monthly Patch Tuesday updates addressing a total of 78 vulnerabilities across its ecosystem. This blog offers a detailed analysis of the vulnerabilities disclosed, with an emphasis on the critical and actively exploited zero-day threats that require immediate attention.
Overview of June 2025 Security Updates
The June 2025 Patch Tuesday addresses:
- Total vulnerabilities: 78
- Zero-day vulnerabilities: 5 (actively exploited)
- Critical severity: 11
- Important severity: 66
- Low severity: 1
Breakdown by Vulnerability Type
| Type | Count |
|---|---|
| Remote Code Execution (RCE) | 28 |
| Elevation of Privilege (EoP) | 21 |
| Information Disclosure | 16 |
| Denial of Service | 5 |
| Security Feature Bypass | 4 |
| Spoofing | 4 |
Zero-Day Vulnerabilities – Actively Exploited
Microsoft confirmed that the following five vulnerabilities are being actively exploited in the wild. These pose a significant risk to enterprise environments and should be prioritized for patching.
1. CVE-2025-30397 – Microsoft Scripting Engine Memory Corruption
- Type: Remote Code Execution
- Severity: Important
- CVSS Score: 7.5
- Attack Vector: Web content rendered via IE mode in Microsoft Edge
- Impact: Arbitrary code execution under user context
- Fix: Included in cumulative update KB5020034
This vulnerability exploits memory corruption in the scripting engine and can be triggered via malicious HTML content. While IE mode is deprecated, it’s still enabled in many enterprise environments, increasing the risk.
2. CVE-2025-30400 – Desktop Window Manager (DWM) Elevation of Privilege
- Type: Elevation of Privilege
- Severity: Important
- CVSS Score: 7.8
- Fix: Addressed in KB5020035
This vulnerability allows attackers with local access to exploit a use-after-free bug in the Desktop Window Manager, granting SYSTEM-level privileges.
3 & 4. CVE-2025-32701 / CVE-2025-32706 – Windows Common Log File System (CLFS)
- Type: Elevation of Privilege
- Severity: Important
- CVSS Score: 7.8 each
- Fix: Both patched in KB5020036
CLFS vulnerabilities have been a recurring threat vector, and these new bugs continue the trend. These vulnerabilities are particularly dangerous due to their history of being exploited in ransomware campaigns.
5. CVE-2025-32709 – Windows Ancillary Function Driver for WinSock
- Type: Elevation of Privilege
- Severity: Important
- CVSS Score: 7.8
- Fix: Included in KB5020037
This vulnerability affects the Windows networking stack and has been used in recent attacks. It enables local attackers to escalate privileges by exploiting the network driver.
Notable Critical Vulnerabilities
In addition to the zero-days, several critical RCE vulnerabilities were also addressed in this patch cycle.
CVE-2025-29813 – Azure DevOps Server RCE
- Type: Remote Code Execution
- CVSS: 10.0 (Critical)
- Fix: Automatically mitigated via Microsoft cloud updates
This issue affects on-premises Azure DevOps Server and allows unauthenticated attackers to execute arbitrary code. Thankfully, this vulnerability was mitigated server-side and did not require manual patching.
Other RCEs:
- Remote Desktop Client vulnerability
- Hyper-V and VMBus privilege escalation flaws
- Office Word and Excel vulnerabilities triggered by opening malicious documents
Update Recommendations
To protect against these threats, the following steps are strongly recommended:
- Deploy June 2025 cumulative updates immediately across Windows client and server systems.
- Prioritize systems exposed to user content (browsers, Office apps, email clients).
- Disable Internet Explorer mode where not required for business functions.
- Monitor endpoint behavior using EDR solutions to detect exploitation attempts.
How to Check Patch Deployment
Use the following PowerShell command to verify the installation of the latest updates:
Get-HotFix | Where-Object {$_.HotFixID -like "KB502003*"}Alternatively, use centralized tools such as Windows Server Update Services (WSUS), Microsoft Intune, or Configuration Manager for patch management.
Conclusion
June 2025’s Patch Tuesday highlights once again the persistent risk posed by elevation of privilege and remote execution vulnerabilities. With five zero-day flaws actively being exploited, organizations must remain vigilant and responsive. These flaws demonstrate that attackers continue to rely on chaining vulnerabilities—starting with phishing or RCE, followed by privilege escalation—to gain total control of systems.
By deploying patches immediately, disabling legacy components like IE mode, and monitoring for unusual activity, enterprises can protect themselves from the most severe exploits identified this month. Always refer to the Microsoft Security Update Guide for the most accurate CVE-to-KB mapping, and follow guidance from CISA and Microsoft regarding high-risk threats.