CVE-2016-8822 in GPU Driver
Summary
by MITRE
All versions of NVIDIA Windows GPU Display Driver contain a vulnerability in the kernel mode layer (nvlddmkm.sys) handler for DxgDdiEscape ID 0x600000E, 0x600000F, and 0x6000010 where a value passed from a user to the driver is used without validation as the index to an internal array, leading to denial of service or potential escalation of privileges.
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Analysis
by VulDB Data Team • 07/09/2019
The vulnerability identified as CVE-2016-8822 represents a critical kernel-mode buffer overflow flaw within NVIDIA's Windows GPU display drivers, specifically affecting the nvlddmkm.sys component that operates at the kernel level. This weakness manifests in the DxgDdiEscape handler functions associated with three distinct escape identifiers 0x600000E, 0x600000F, and 0x6000010, which are part of the Windows Display Driver Model interface. The flaw stems from inadequate input validation mechanisms within the kernel-mode driver code where user-supplied values are directly utilized as array indices without proper bounds checking or sanitization. This design oversight creates a scenario where maliciously crafted input can cause the driver to access memory locations outside the intended array boundaries, potentially leading to system instability or unauthorized privilege escalation. The vulnerability affects all versions of NVIDIA Windows GPU drivers, making it particularly concerning given the widespread deployment of these graphics drivers across enterprise and consumer environments.
The technical exploitation of this vulnerability occurs through the manipulation of graphics API calls that utilize the DxgDdiEscape interface, which serves as a communication channel between user-mode applications and kernel-mode driver components. When user applications submit escape commands with specifically crafted indices, the kernel-mode handler processes these values without validation, treating them as legitimate array access parameters. This unchecked user input can cause the driver to traverse memory locations beyond the allocated array bounds, potentially resulting in memory corruption that may manifest as system crashes, blue screen errors, or more severe privilege escalation attacks. The vulnerability's impact is amplified by the fact that kernel-mode code operates with the highest privilege level, meaning successful exploitation could allow attackers to execute arbitrary code with system-level privileges. According to CWE classification, this vulnerability maps to CWE-129 which describes "Improper Validation of Array Index" and CWE-787 which covers "Out-of-bounds Write" in kernel-mode contexts. The ATT&CK framework categorizes this under T1068 for "Exploitation for Privilege Escalation" and T1499 for "Endpoint Denial of Service" as it can be leveraged for both system disruption and unauthorized access.
The operational impact of CVE-2016-8822 extends beyond simple denial of service scenarios, as it presents a significant vector for privilege escalation attacks that could compromise entire computing systems. When exploited successfully, the vulnerability allows attackers to gain kernel-level privileges, potentially enabling them to install persistent backdoors, modify system files, or access sensitive data. The attack surface is particularly broad since graphics drivers are essential components of Windows systems, and the vulnerability can be triggered through legitimate graphics applications or malicious software that leverages graphics APIs. Organizations running affected NVIDIA drivers face substantial risk, as the vulnerability can be exploited remotely through compromised applications or locally through malicious code execution. The potential for system instability means that even unsuccessful exploitation attempts could cause denial of service, disrupting business operations and potentially leading to data loss or service interruption. Security researchers have noted that the vulnerability's exploitation is relatively straightforward, requiring only knowledge of the specific escape command identifiers and understanding of the driver's memory layout to craft effective attacks.
Mitigation strategies for CVE-2016-8822 primarily focus on immediate driver updates from NVIDIA, which address the root cause by implementing proper input validation and bounds checking mechanisms in the affected kernel-mode handlers. System administrators should prioritize patching all affected systems, particularly those running older NVIDIA driver versions that lack the security fixes introduced in subsequent releases. Additional protective measures include implementing application whitelisting policies that restrict execution of untrusted graphics applications, monitoring for unusual graphics API calls that might indicate exploitation attempts, and maintaining comprehensive system monitoring to detect potential privilege escalation activities. Network segmentation and least-privilege access controls can help limit the potential impact if exploitation occurs, while endpoint detection and response solutions should be configured to monitor for kernel-mode memory access anomalies. Organizations should also consider implementing driver signature enforcement and disabling unnecessary graphics features that might expose additional attack vectors. The vulnerability demonstrates the critical importance of kernel-mode security practices and proper input validation, as even minor oversights in driver code can lead to severe system compromise. Regular security assessments of graphics driver components and comprehensive vulnerability management programs are essential for maintaining system security posture against similar kernel-level threats.