CVE-2018-6248 in Windows GPU Display Driver
Summary
by MITRE
NVIDIA Windows GPU Display Driver contains a vulnerability in the kernel mode layer handler for DxgkDdiEscape where the software uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer which may lead to denial of service or possible escalation of privileges.
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Analysis
by VulDB Data Team • 01/20/2020
The vulnerability identified as CVE-2018-6248 resides within the NVIDIA Windows GPU Display Driver, specifically within the kernel mode layer handler known as DxgkDdiEscape. This flaw represents a classic buffer overflow condition that occurs when the driver processes escape commands sent from user-mode applications to the kernel-mode display driver. The issue stems from improper validation of buffer lengths during the execution of graphics operations, creating a potential attack surface that could be exploited by malicious actors. The vulnerability is particularly concerning because it operates at the kernel level, where the privilege separation between user and system modes is critical for maintaining system integrity and security.
The technical implementation of this vulnerability manifests through the DxgkDdiEscape function which handles escape sequences for graphics operations. When processing these escape commands, the driver performs sequential read or write operations on buffers without proper bounds checking against the actual buffer size. This incorrect length handling allows attackers to manipulate memory access patterns that extend beyond the intended buffer boundaries. The flaw essentially creates a situation where memory locations adjacent to the allocated buffer can be accessed, modified, or read, potentially leading to arbitrary code execution or system instability. This type of vulnerability is categorized under CWE-129 as "Improper Validation of Array Index" and falls under the broader category of buffer overflow conditions that can lead to privilege escalation.
The operational impact of CVE-2018-6248 extends beyond simple denial of service scenarios to include potential privilege escalation opportunities that could allow attackers to execute code with kernel-level privileges. When exploited, this vulnerability could enable an attacker to gain unauthorized access to system resources, modify critical system files, or establish persistent backdoors within the operating system. The nature of the kernel-mode execution means that successful exploitation could result in complete system compromise, making this vulnerability particularly dangerous in enterprise environments where GPU acceleration is commonly used. Attackers could leverage this flaw to bypass standard security controls, escalate privileges from standard user accounts to SYSTEM level access, and potentially deploy additional malware or tools for further exploitation.
Mitigation strategies for CVE-2018-6248 should focus on both immediate patching and operational security measures. The most effective solution involves applying the official NVIDIA driver updates that address this specific vulnerability by correcting the buffer length validation logic within the DxgkDdiEscape handler. System administrators should prioritize patch deployment across all affected systems, particularly those running Windows operating systems with NVIDIA GPU drivers. Additional defensive measures include implementing application whitelisting to restrict execution of potentially malicious graphics operations, monitoring for unusual graphics driver behavior through endpoint detection and response tools, and ensuring that systems are running the latest security patches from Microsoft and NVIDIA. From an ATT&CK perspective, this vulnerability aligns with techniques such as T1068 for local privilege escalation and T1059 for command and scripting interpreter usage, making it a significant concern for organizations implementing threat hunting and incident response protocols.