CVE-2016-8821 in GPU Driver
Summary
by MITRE
All versions of NVIDIA Windows GPU Display Driver contain a vulnerability in the kernel mode layer handler for DxgDdiEscape where improper access controls may allow a user to access arbitrary physical memory, leading to an escalation of privileges.
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Analysis
by VulDB Data Team • 07/09/2019
The vulnerability identified as CVE-2016-8821 resides within the NVIDIA Windows GPU Display Driver kernel mode layer, specifically within the DxgDdiEscape handler component. This flaw represents a critical access control weakness that fundamentally compromises the security boundaries between user mode and kernel mode execution environments. The vulnerability affects all versions of the NVIDIA Windows GPU Display Driver, making it particularly concerning given the widespread deployment of NVIDIA graphics hardware across enterprise and consumer environments. The issue stems from inadequate validation of input parameters within the kernel mode handler, creating an opportunity for malicious code to manipulate the graphics driver interface and subsequently access protected system resources.
The technical exploitation of this vulnerability occurs through the DxgDdiEscape function which serves as an escape mechanism for graphics driver operations. When a user process invokes this function with specially crafted parameters, the kernel mode handler fails to properly validate the memory access requests, allowing unauthorized physical memory access. This represents a classic privilege escalation flaw where user-level processes can manipulate kernel mode components to gain access to physical memory addresses that should be protected. The vulnerability directly maps to CWE-284 Access Control Issues, specifically involving improper access controls in kernel mode components. The flaw essentially creates a pathway for arbitrary code execution at kernel level, bypassing standard Windows security mechanisms such as address space layout randomization and data execution prevention.
The operational impact of CVE-2016-8821 extends beyond simple privilege escalation to encompass complete system compromise capabilities. An attacker with local user privileges can leverage this vulnerability to read and write to any physical memory location, potentially accessing sensitive kernel data structures, memory containing passwords or encryption keys, or even modifying critical system components. This vulnerability enables attackers to bypass modern security mitigations including kernel address space layout randomization and kernel mode exploit protection mechanisms. The threat landscape for this vulnerability includes both sophisticated nation-state actors and organized cybercriminal groups seeking to establish persistent backdoors or extract sensitive information from targeted systems. The impact is particularly severe in enterprise environments where NVIDIA graphics drivers are commonly deployed across workstations and servers, potentially providing attackers with a reliable method for maintaining persistence and escalating privileges across multiple systems.
Mitigation strategies for CVE-2016-8821 primarily focus on immediate driver updates from NVIDIA, which address the root cause through proper input validation and access control enforcement within the DxgDdiEscape handler. System administrators should prioritize patch deployment across all affected systems, particularly those running in high-risk environments such as financial institutions, government agencies, or critical infrastructure organizations. Additional mitigations include implementing application whitelisting policies to restrict execution of unauthorized graphics driver interfaces, enabling Windows security features such as Control Flow Guard and Driver Signature Enforcement, and monitoring for suspicious kernel mode activity through endpoint detection and response solutions. Organizations should also consider network segmentation and access control measures to limit the potential impact of successful exploitation, as the vulnerability does not require network connectivity for exploitation but rather relies on local user access. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting kernel-mode privilege escalation through driver manipulation, making it a significant concern for security teams implementing threat hunting and incident response procedures.