CVE-2020-5981 in Windows GPU Display Driver
Summary
by MITRE • 10/04/2020
NVIDIA Windows GPU Display Driver, all versions, contains a vulnerability in the DirectX11 user mode driver (nvwgf2um/x.dll), in which a specially crafted shader can cause an out of bounds access, which may lead to denial of service or code execution.
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Analysis
by VulDB Data Team • 11/16/2020
The vulnerability identified as CVE-2020-5981 affects NVIDIA Windows GPU Display Drivers across all versions and resides within the DirectX11 user mode driver component known as nvwgf2um/x.dll. This flaw represents a critical security issue that stems from improper input validation within the graphics processing pipeline, specifically when handling specially crafted shader code. The vulnerability manifests as an out-of-bounds memory access condition that occurs during shader execution, creating potential pathways for malicious exploitation. The affected driver component operates in user mode, meaning that successful exploitation could potentially allow attackers to execute arbitrary code with the privileges of the affected application or system process.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write vulnerabilities. These classifications indicate that the flaw involves memory access violations that can occur when processing graphics shaders, particularly those designed to exploit the boundaries of allocated memory regions. The vulnerability operates at the intersection of graphics processing and memory management, where shader compilation and execution routines fail to properly validate input parameters before accessing memory locations. This type of vulnerability is particularly dangerous in graphics contexts because shaders are often complex programs that can be crafted to manipulate memory access patterns in unexpected ways, potentially leading to arbitrary code execution or system instability.
From an operational impact perspective, this vulnerability presents significant risks to system security and availability. The potential for denial of service means that an attacker could cause system crashes or rendering failures that would disrupt normal graphics operations, while the code execution capability could allow for privilege escalation or system compromise. The vulnerability affects all versions of NVIDIA Windows GPU drivers, indicating that it represents a fundamental flaw in the driver architecture rather than a specific version-related issue. This broad impact means that organizations with NVIDIA graphics hardware across their network infrastructure could be vulnerable to exploitation, particularly in environments where users have the ability to execute arbitrary code or where graphics-intensive applications are commonly used.
The exploitation of this vulnerability would likely follow patterns consistent with the ATT&CK framework's technique T1059, which involves executing malicious code through command and scripting interpreters, or potentially T1068, which covers exploit development for privilege escalation. The attack surface is primarily through graphics applications or malware that can leverage the DirectX11 user mode driver to execute malicious shaders. Organizations should implement comprehensive mitigation strategies including regular driver updates from NVIDIA, which would address the underlying memory access validation issues, network segmentation to limit exposure, and monitoring for unusual graphics processing behavior. Additionally, security teams should consider implementing application whitelisting policies that restrict execution of potentially malicious shader code, particularly in environments where graphics processing is not essential for normal operations. The vulnerability demonstrates the importance of robust input validation in graphics driver components and highlights the need for continuous security assessment of graphics processing pipelines to prevent similar issues in future implementations.