Analysis Summary

A critical elevation of privilege vulnerability, CVE-2025-33067, has been identified in the Windows Task Scheduler, affecting a wide range of Windows operating systems, from Windows 10 Version 1607 to Windows 11 24H2 and Windows Server 2016 through 2025. This flaw, with a CVSS v3.1 score of high, is rated "Important" due to its ability to allow local attackers to escalate privileges to SYSTEM level access, without needing prior administrative rights or user interaction. Discovered by a security researcher, the vulnerability stems from improper privilege management within the Windows Kernel’s scheduling component, allowing unauthorized users to exploit certain scheduled task permissions under specific conditions.

The vulnerability is particularly dangerous due to its low complexity (AC L) and no prior privileges (PR: N) requirement, making it an easy and attractive target once attackers gain local access (AV:L). The CVSS vector string indicates high impact on confidentiality, integrity, and availability, aligning with the fact that SYSTEM-level privileges provide unrestricted control over a device. This makes it crucial for organizations to act swiftly, especially on endpoints that handle sensitive data or are accessible by untrusted users. Potential attack vectors include gaining initial access through phishing, physical access, or chaining with other vulnerabilities.

In response, Microsoft released comprehensive security updates on June 10, 2025, covering 27 affected configurations across all supported Windows platforms. Notable updates include KB5061010 for Windows Server 2016/Windows 10 Version 1607, KB5060998 for early Windows 10 builds, and KB5060842/KB5060841 for Windows Server 2025 and Windows 11 24H2. Other updates, such as KB5060999 and KB5060533, target Windows 11 and Windows 10 newer versions, respectively. These patches are crucial to prevent any potential exploitation, especially as Microsoft currently assesses the threat as “Exploitation Less Likely,” with no known active attacks observed in the wild.

While deploying patches remains the top priority, organizations are advised to implement additional defensive measures. These include network segmentation, enforcing the principle of least privilege, and closely monitoring Task Scheduler activity for anomalies. Administrators should also audit all existing scheduled tasks to ensure proper permission configurations and limit unnecessary or misconfigured tasks that could serve as an entry point for attackers. Despite the current low exploitation risk, the ease of abuse and the broad scope of affected systems make this vulnerability a high-priority issue for enterprise environments.

Impact

• Privilege Escalation
• Gain Access

Indicators of Compromise

CVE

• CVE-2025-33067

Affected Vendors

Remediation

• Use Microsoft Automatic Update to apply the appropriate patch for your system, or the Microsoft Security Update Guide to search for available patches.
• Review all scheduled tasks on endpoints and servers. Remove or secure tasks that grant elevated privileges unnecessarily or lack proper access controls.
• Enforce the Principle of Least Privilege (PoLP)
• Restrict user permissions to only what is necessary. Avoid assigning administrative privileges unless absolutely required.
• Use endpoint detection tools or Windows Event Logs to monitor for unusual Task Scheduler activity that may indicate privilege escalation attempts.
• Isolate critical systems and high-value assets from user-accessible machines to limit lateral movement after initial access.
• Deploy Endpoint Detection and Response (EDR) solutions capable of detecting suspicious local privilege escalation behavior.
• Since local access is required, reduce attack surface by educating users on phishing and monitoring for social engineering tactics used to gain foothold.
• Ensure that future vulnerabilities are mitigated quickly by maintaining a consistent and timely patch deployment strategy.