CVE-2019-5686 in Windows GPU Display Driver
Summary
by MITRE
NVIDIA Windows GPU Display Driver (all versions) contains a vulnerability in the kernel mode layer (nvlddmkm.sys) handler for DxgkDdiEscape in which the software uses an API function or data structure in a way that relies on properties that are not always guaranteed to be valid, which may lead to denial of service.
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Analysis
by VulDB Data Team • 07/22/2020
The vulnerability identified as CVE-2019-5686 resides within the NVIDIA Windows GPU Display Driver kernel mode layer component known as nvlddmkm.sys. This flaw specifically affects the DxgkDdiEscape handler function which serves as an interface between the display driver and the Windows kernel for executing escape operations. The vulnerability manifests when the driver processes certain escape commands that utilize API functions or data structures whose properties are not consistently validated or guaranteed to remain valid throughout execution contexts. This particular weakness falls under the category of improper validation of prerequisites as classified by CWE-252, representing a fundamental failure in input validation that can lead to unpredictable system behavior.
The technical exploitation of this vulnerability occurs within the kernel mode execution context of the graphics driver, where the DxgkDdiEscape handler processes escape operations that allow direct communication between user mode applications and kernel mode driver components. When malformed or unexpected parameters are passed to this handler, the driver's reliance on certain API properties that may not always be present or valid causes the system to enter an unstable state. The vulnerability specifically targets the kernel mode driver's handling of escape commands, which are typically used for specialized graphics operations, driver configuration changes, or hardware-specific functionality. This creates a scenario where an attacker can potentially trigger a denial of service condition that may result in system crashes, display driver failures, or complete system instability.
From an operational impact perspective, this vulnerability represents a significant concern for Windows systems utilizing NVIDIA graphics hardware, particularly in enterprise environments where system stability and uptime are critical. The denial of service condition can manifest as complete graphics driver failures, system blue screens, or complete system crashes that require manual intervention to restore normal operation. Attackers could potentially exploit this vulnerability through malicious applications or games that intentionally send malformed escape commands to the graphics driver, causing system instability. The impact extends beyond simple service disruption as it can affect critical business operations, particularly in environments where graphics-intensive applications are common such as CAD workstations, video editing systems, or gaming platforms. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1489 for denial of service, as it can be leveraged to cause system-wide service interruption.
Mitigation strategies for CVE-2019-5686 should prioritize immediate driver updates from NVIDIA, as the company has released patches addressing this specific vulnerability in subsequent driver versions. System administrators should implement strict patch management policies ensuring all NVIDIA graphics drivers are updated to versions that contain the necessary fixes. Additionally, monitoring systems should be configured to detect unusual patterns of graphics driver crashes or system instability that might indicate exploitation attempts. Network segmentation and application whitelisting can help prevent unauthorized applications from accessing graphics driver interfaces, though this approach requires careful implementation to avoid disrupting legitimate system functionality. Organizations should also consider implementing behavioral monitoring solutions that can detect anomalous escape command usage patterns. The vulnerability's nature as a kernel-mode issue means that traditional user-mode protections are insufficient, requiring system-level security measures and proper driver hardening practices to prevent exploitation. Regular security assessments of graphics driver configurations and maintaining up-to-date system monitoring capabilities remain essential for detecting and preventing exploitation of this type of kernel vulnerability.