CVE-2019-5666 in Windows GPU Display Driver
Summary
by MITRE
NVIDIA Windows GPU Display Driver contains a vulnerability in the kernel mode layer (nvlddmkm.sys) create context command DDI DxgkDdiCreateContext in which the product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array, which may lead to denial of service or escalation of privileges.
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Analysis
by VulDB Data Team • 05/13/2020
The vulnerability identified as CVE-2019-5666 resides within the NVIDIA Windows GPU Display Driver kernel mode component known as nvlddmkm.sys. This flaw specifically manifests in the DxgkDdiCreateContext DDI command implementation where the driver fails to properly validate array indices derived from untrusted input. The issue stems from improper bounds checking mechanisms that allow malicious input to potentially manipulate memory access patterns within the kernel mode driver. This vulnerability represents a critical security weakness that affects the core graphics subsystem of Windows operating systems when utilizing NVIDIA GPU hardware, creating potential attack vectors that could be exploited by malicious actors to compromise system integrity.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of array index bounds, and can be categorized under the broader ATT&CK technique of privilege escalation through kernel-mode exploitation. When the DxgkDdiCreateContext command processes incoming parameters, it accepts untrusted data that should represent valid array indices but fails to validate whether these indices fall within acceptable memory boundaries. This validation failure creates a potential for out-of-bounds memory access scenarios where an attacker could manipulate the index calculation to reference memory locations outside the intended array boundaries. The vulnerability essentially allows an attacker to craft input that could cause the driver to access memory in unintended ways, potentially leading to memory corruption or unauthorized privilege escalation.
The operational impact of CVE-2019-5666 extends beyond simple denial of service conditions to encompass serious privilege escalation capabilities that could enable attackers to gain elevated system privileges. When exploited, this vulnerability could allow an attacker to execute arbitrary code within kernel mode, effectively bypassing standard operating system security mechanisms and potentially providing full system compromise. The vulnerability affects NVIDIA GPU drivers across multiple Windows versions and could be exploited through various attack vectors including malicious graphics applications, compromised software installations, or direct kernel exploitation techniques. The nature of the flaw means that even legitimate applications could inadvertently trigger the vulnerability if they provide malformed input to the graphics subsystem.
Mitigation strategies for this vulnerability should include immediate patching of affected NVIDIA GPU drivers to the latest versions that contain the necessary security fixes. System administrators should implement comprehensive monitoring for unusual graphics driver behavior or memory access patterns that might indicate exploitation attempts. Additional protective measures include enabling kernel mode code integrity checks, restricting graphics driver access through application whitelisting policies, and maintaining regular security updates for all GPU driver components. Organizations should also consider implementing network segmentation and privilege separation to limit the potential impact of successful exploitation. The vulnerability demonstrates the critical importance of proper input validation in kernel mode components and highlights the need for comprehensive security testing of graphics driver subsystems that handle untrusted input from various application sources.