CVE-2019-5667 in Windows GPU Display Driver
Summary
by MITRE
NVIDIA Windows GPU Display Driver contains a vulnerability in the kernel mode layer (nvlddmkm.sys) handler for DxgkDdiSetRootPageTable in which the application dereferences a pointer that it expects to be valid, but is NULL, which may lead to code execution, denial of service or escalation of privileges.
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Analysis
by VulDB Data Team • 05/13/2020
The vulnerability identified as CVE-2019-5667 resides within the NVIDIA Windows GPU Display Driver kernel mode component known as nvlddmkm.sys. This flaw specifically impacts the DxgkDdiSetRootPageTable handler function which operates within the kernel mode layer of the graphics driver architecture. The vulnerability represents a classic null pointer dereference issue that occurs when the driver processes graphics kernel functions through the DirectX graphics kernel interface. Such vulnerabilities are particularly dangerous because they exist within the kernel mode portion of the driver, which operates with the highest privilege level and direct access to system resources. The affected handler function processes page table operations that are fundamental to graphics memory management and GPU virtual memory handling within the Windows operating system.
The technical execution of this vulnerability occurs when the DxgkDdiSetRootPageTable function receives input parameters that result in a NULL pointer being dereferenced during normal graphics processing operations. This type of flaw typically arises from inadequate input validation within kernel mode drivers where the driver code assumes certain pointers will always contain valid addresses without proper null checks. The vulnerability can be triggered through legitimate graphics operations that utilize the DirectX graphics kernel interface, making it particularly concerning as it may be exploitable through normal user activities or malicious applications that leverage graphics APIs. According to CWE classification, this represents a CWE-476: NULL Pointer Dereference vulnerability, which is categorized under the broader weakness of improper null pointer handling in kernel mode components. The attack surface is expanded when considering that graphics drivers are frequently loaded and executed with high privileges, making successful exploitation potentially catastrophic.
The operational impact of CVE-2019-5667 extends across multiple security domains including privilege escalation, denial of service, and potential code execution. When exploited successfully, this vulnerability could allow an attacker to escalate privileges from user level to kernel level, effectively providing complete system compromise. The denial of service aspect manifests as system crashes or hangs when the driver encounters the null pointer dereference condition during graphics processing. Code execution capabilities arise from the kernel mode nature of the vulnerability, where successful exploitation could enable attackers to inject and execute arbitrary code with the highest system privileges. This vulnerability directly maps to ATT&CK technique T1068: Exploitation for Privilege Escalation, as the kernel mode execution context provides a clear path for privilege elevation. Additionally, the vulnerability affects the integrity and availability of the graphics subsystem, potentially impacting all applications that rely on GPU acceleration.
Mitigation strategies for CVE-2019-5667 should prioritize immediate driver updates from NVIDIA, as the company has released patches addressing this specific vulnerability. System administrators should implement comprehensive patch management procedures to ensure all affected systems receive the latest driver versions. Network segmentation and access controls should be employed to limit potential exploitation vectors, particularly in environments where graphics-intensive applications are prevalent. Monitoring for suspicious graphics kernel activity and anomalous system behavior can help detect exploitation attempts. The vulnerability demonstrates the importance of kernel mode input validation and proper error handling in device drivers, as highlighted in industry best practices for secure driver development. Organizations should also consider implementing application whitelisting policies that restrict execution of untrusted graphics-related code, and maintain regular security assessments of their graphics driver configurations. System hardening measures including disabling unnecessary graphics features and restricting user access to graphics kernel interfaces can further reduce the attack surface. The vulnerability serves as a reminder of the critical security implications of kernel mode flaws and the necessity for rigorous security testing of device drivers before deployment in production environments.