CVE-2018-6251 in Windows GPU Display Driver
Summary
by MITRE
NVIDIA Windows GPU Display Driver contains a vulnerability in DirectX 10 Usermode driver, where specially crafted pixel shader can cause writing to unallocated memory leading to denial of service or potential code execution.
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Analysis
by VulDB Data Team • 01/20/2020
The vulnerability identified as CVE-2018-6251 resides within NVIDIA's Windows GPU Display Driver implementation, specifically affecting the DirectX 10 Usermode driver component. This flaw represents a critical security issue that arises from insufficient input validation within the graphics processing pipeline, creating a potential pathway for malicious actors to exploit the system through crafted graphics operations. The vulnerability manifests when the driver processes specially crafted pixel shaders that contain malformed or unexpected data structures, leading to improper memory management during graphics rendering operations.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-787, which covers out-of-bounds write errors. The flaw occurs during the processing of pixel shader instructions where the driver fails to properly validate shader parameters before executing memory operations. When a malicious pixel shader is presented to the graphics driver, the insufficient bounds checking allows the shader code to write data beyond the allocated memory boundaries, potentially corrupting adjacent memory regions or triggering system instability. This memory corruption can manifest in various ways including application crashes, system hangs, or in more severe cases, arbitrary code execution within the context of the graphics driver process.
From an operational perspective, this vulnerability presents significant risks to system stability and security posture. The potential for denial of service means that legitimate users could experience system crashes or complete system lockups during graphics-intensive operations, while the code execution possibility opens the door for privilege escalation attacks. Attackers could leverage this vulnerability to execute malicious code with the privileges of the graphics driver, which typically runs with high system privileges. The impact extends beyond simple system disruption as the vulnerability affects the core graphics rendering functionality that many applications depend upon, potentially compromising the entire system security model.
The attack surface for this vulnerability is substantial given that DirectX 10 is widely supported across various Windows operating systems and graphics applications. The vulnerability is particularly concerning because it operates at the usermode driver level, meaning that exploitation could occur through legitimate graphics applications or even web browsers that utilize hardware acceleration. This vulnerability is categorized under the ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', as successful exploitation could lead to elevated privileges within the system. Mitigation strategies should focus on immediate driver updates from NVIDIA, implementation of application whitelisting policies, and monitoring for unusual graphics processing patterns that might indicate exploitation attempts. System administrators should also consider implementing additional security controls such as disabling hardware acceleration for untrusted applications and maintaining comprehensive system monitoring to detect potential exploitation attempts.