CVE-2021-1094 in GPU Display Driver
Summary
by MITRE • 07/22/2021
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer (nvlddmkm.sys) handler for DxgkDdiEscape where an out of bounds array access may lead to denial of service or information disclosure.
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Analysis
by VulDB Data Team • 07/26/2021
The vulnerability identified as CVE-2021-1094 resides within NVIDIA's GPU Display Driver ecosystem affecting both Windows and Linux operating systems through the kernel mode layer component known as nvlddmkm.sys. This flaw manifests specifically within the DxgkDdiEscape handler which serves as a critical interface for graphics driver operations. The vulnerability stems from inadequate bounds checking mechanisms that fail to validate array access parameters, creating a potential entry point for malicious actors to exploit the graphics subsystem. According to CWE-129, this represents an implementation flaw where insufficient validation of array indices leads to memory access violations that can be leveraged for system compromise.
The technical exploitation of this vulnerability occurs when the DxgkDdiEscape handler processes malformed input data without proper boundary validation, potentially allowing an attacker to trigger out of bounds array access conditions. This flaw operates at the kernel level within the graphics driver's device driver model, making it particularly dangerous as it can execute with elevated privileges typically reserved for system-level operations. The vulnerability's impact extends beyond simple denial of service as it may also enable information disclosure attacks where sensitive memory contents could be accessed through carefully crafted escape sequences. The ATT&CK framework categorizes this under privilege escalation techniques through driver manipulation, specifically targeting the system's graphics processing capabilities.
Operational consequences of this vulnerability present significant risks to organizations relying on NVIDIA graphics hardware, particularly in enterprise environments where system stability and data integrity are paramount. The denial of service aspect can result in complete graphics subsystem failure, forcing system reboots and disrupting user productivity while the information disclosure component could potentially expose sensitive kernel memory structures or proprietary driver information. Attackers could leverage this vulnerability to establish persistent access points within the system or to escalate privileges beyond normal user boundaries. The cross-platform nature of this vulnerability means that both Windows and Linux systems using NVIDIA graphics drivers are equally at risk, complicating mitigation efforts across diverse computing environments.
Mitigation strategies for CVE-2021-1094 should prioritize immediate driver updates from NVIDIA, which typically include patched versions of the nvlddmkm.sys component with enhanced bounds checking mechanisms. System administrators should implement comprehensive monitoring for unusual graphics driver behavior and establish baseline configurations that can detect potential exploitation attempts. The vulnerability's kernel-level nature necessitates robust system integrity monitoring solutions that can detect unauthorized modifications to graphics driver components. Organizations should also consider implementing network segmentation to limit potential lateral movement if exploitation occurs, while maintaining detailed audit logs of graphics driver interactions. Additionally, regular security assessments of graphics driver configurations should be conducted to ensure that all systems remain protected against similar vulnerabilities in the graphics processing subsystem.