CVE-2016-7271 in Windows
Summary
by MITRE
The Secure Kernel Mode implementation in Microsoft Windows 10 Gold, 1511, and 1607 and Windows Server 2016 allows local users to bypass the virtual trust level (VTL) protection mechanism via a crafted application, aka "Secure Kernel Mode Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 09/23/2024
The Secure Kernel Mode implementation in Microsoft Windows operating systems represents a critical security component designed to protect the most sensitive system operations from unauthorized access and manipulation. This mechanism establishes virtual trust levels that create isolated execution environments where privileged operations can occur securely. The vulnerability described in CVE-2016-7271 specifically targets the VTL protection mechanism within the Secure Kernel Mode, which is intended to prevent unauthorized elevation of privileges by maintaining strict isolation between different security domains. When properly functioning, VTL ensures that user-mode applications cannot directly access or manipulate kernel-mode operations that should remain protected from potential exploitation.
The technical flaw in this vulnerability stems from an insufficient validation mechanism within the Secure Kernel Mode implementation that fails to properly enforce the virtual trust level boundaries. Attackers can craft malicious applications that exploit this weakness to bypass the protection mechanisms that should prevent privilege escalation. This occurs through carefully constructed code sequences that manipulate the kernel-mode execution environment in ways that the VTL protection was designed to prevent. The vulnerability essentially allows a local user to execute code with elevated privileges that would normally be restricted, effectively breaking down the security isolation that separates different trust levels within the operating system's kernel.
The operational impact of this vulnerability is severe as it provides local users with the ability to achieve privilege escalation without requiring physical access or complex attack vectors. This means that any user with access to the system can potentially exploit this vulnerability to gain higher-level system privileges, potentially leading to complete system compromise. The vulnerability affects multiple Windows versions including Windows 10 Gold, 1511, and 1607, as well as Windows Server 2016, indicating a widespread impact across Microsoft's product line. Attackers could leverage this vulnerability to install persistent backdoors, modify system files, access sensitive data, or establish footholds for further attacks within the network environment.
This vulnerability aligns with CWE-284, which describes improper access control mechanisms, and represents a classic example of how virtual trust level implementations can fail to provide adequate protection when boundary checks are insufficient. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques that exploit weaknesses in kernel-mode protection mechanisms. The attack vector is particularly concerning because it operates entirely within the local system context, making detection more difficult and the attack surface broader than typical remote exploitation scenarios. Organizations should implement immediate mitigations including applying Microsoft security updates, monitoring for unusual privilege escalation activities, and reviewing system access controls to prevent unauthorized users from gaining elevated privileges through this vulnerability.