CVE-2019-7245 in GPU-Z
Summary
by MITRE
An issue was discovered in GPU-Z.sys in TechPowerUp GPU-Z before 2.23.0. The vulnerable driver exposes a wrmsr instruction via an IOCTL and does not properly filter the Model Specific Register (MSR). Allowing arbitrary MSR writes can lead to Ring-0 code execution and escalation of privileges.
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Analysis
by VulDB Data Team • 05/11/2024
The vulnerability identified as CVE-2019-7245 affects GPU-Z.sys, a kernel-mode driver component of TechPowerUp GPU-Z software version prior to 2.23.0. This driver serves as an interface between the operating system and graphics hardware, providing system information and monitoring capabilities. The flaw manifests in the driver's implementation of IOCTL (Input/Output Control) handling, specifically through the exposure of the wrmsr instruction which allows direct write access to Model Specific Registers. This represents a critical security oversight in kernel-mode software where proper privilege validation and input sanitization mechanisms are absent. The vulnerability falls under CWE-119 Improper Restriction of Operations within the Buffer Boundary, and more specifically aligns with CWE-787 Out-of-bounds Write, as the driver fails to properly validate the MSR addresses being written to. The exposure of wrmsr functionality through an IOCTL interface creates an attack surface that enables malicious actors to execute arbitrary code at the highest privilege level.
The technical implementation of this vulnerability stems from the driver's lack of proper MSR address filtering and validation mechanisms. When a user-level application sends an IOCTL command to the GPU-Z.sys driver, the driver accepts the requested MSR address without adequate validation, allowing writes to any MSR location within the processor's address space. This bypasses normal kernel security protections and creates a direct pathway for privilege escalation attacks. The wrmsr instruction, when executed in kernel mode, can modify critical processor control registers including those governing memory management, interrupt handling, and privilege level enforcement. This capability enables attackers to manipulate the processor's operating environment in ways that can lead to complete system compromise. The vulnerability essentially provides an unrestricted backdoor into the kernel execution environment, making it a prime target for exploitation in advanced persistent threat campaigns and privilege escalation attacks.
The operational impact of CVE-2019-7245 is severe and far-reaching, as it allows attackers to achieve Ring-0 code execution without requiring any user interaction or elevated privileges. This means that any user with access to the system can potentially exploit this vulnerability to gain complete administrative control over the machine. The implications extend beyond simple privilege escalation to include full system compromise, data exfiltration, and the ability to install rootkits or other malicious software that operates below the detection capabilities of standard security tools. The vulnerability can be exploited through various attack vectors including malicious software installation, web-based attacks, or even physical access scenarios where an attacker can run custom applications against the vulnerable driver. This type of vulnerability is particularly dangerous in enterprise environments where system administrators might inadvertently install outdated versions of GPU-Z software, creating persistent attack vectors that remain undetected for extended periods.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening. The primary and most effective mitigation is updating to TechPowerUp GPU-Z version 2.23.0 or later, which includes proper MSR validation and filtering mechanisms. System administrators should also implement driver signature enforcement policies and ensure that only signed, verified drivers are loaded into the kernel space. Additional protective measures include implementing kernel-mode exploit protection features such as Control Flow Guard and Driver Verifier, which can detect and prevent abnormal driver behavior. From a defensive perspective, organizations should monitor for any instances of the vulnerable GPU-Z.sys driver in their environments and establish automated patch management processes. The vulnerability also highlights the importance of proper kernel-mode security practices including input validation, privilege separation, and least-privilege execution models. Security teams should consider implementing behavioral monitoring solutions that can detect anomalous MSR access patterns and potential exploitation attempts. This vulnerability demonstrates the critical need for proper security testing of kernel-mode components and adherence to secure coding practices that prevent dangerous instructions from being exposed through user-accessible interfaces.