CVE-2017-8746 in Windows
Summary
by MITRE
Windows Device Guard in Windows 10 1607, 1703, and Windows Server 2016 allows A security feature bypass vulnerability due to how PowerShell exposes functions and processes user supplied code, aka "Device Guard Security Feature Bypass Vulnerability".
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/08/2024
The CVE-2017-8746 vulnerability represents a critical security feature bypass in Windows Device Guard implementations across Windows 10 versions 1607 and 1703, as well as Windows Server 2016. This flaw specifically targets the mechanism by which PowerShell interfaces with system functions and processes user-supplied code, creating an avenue for attackers to circumvent the intended security protections. Device Guard was designed to prevent the execution of unauthorized code and establish a trusted execution environment, making this bypass particularly concerning for enterprise security postures.
The technical exploitation of this vulnerability stems from how PowerShell handles function exposure and code processing within the Device Guard framework. When PowerShell processes user-supplied code, it inadvertently creates opportunities for malicious actors to leverage existing system functions that should otherwise be restricted or isolated. This occurs through improper validation of code execution contexts and insufficient boundary checking between trusted and untrusted code segments. The vulnerability essentially allows attackers to execute arbitrary code that would normally be blocked by Device Guard policies, effectively neutralizing the security controls that organizations rely upon to prevent malicious software execution.
From an operational impact perspective, this vulnerability exposes organizations to significant risk as it undermines the fundamental security architecture designed to protect against script-based attacks and malicious code execution. Attackers can exploit this flaw to bypass application control policies, execute malicious PowerShell scripts, and potentially escalate privileges within the system. The vulnerability affects the core Windows security infrastructure, meaning that organizations with robust Device Guard implementations may find their protections rendered ineffective. This creates a cascading security risk where other security controls that depend on Device Guard functionality may also become compromised.
The vulnerability aligns with CWE-693, which addresses protection mechanism failures, and relates to ATT&CK technique T1059.001 for command and scripting interpreter usage. Organizations should implement immediate mitigations including deploying the relevant Microsoft security updates, reviewing and strengthening Device Guard policies, and implementing additional runtime monitoring controls. Network segmentation and application whitelisting should be reinforced as additional protective measures. Regular security assessments should verify that Device Guard configurations remain effective against such bypass techniques. The vulnerability demonstrates the complexity of modern security architectures where seemingly isolated components can create unexpected attack vectors when integrated within broader system frameworks.