CVE-2019-7246 in ATI Diagnostics Hardware Abstraction Sys Overclocking Utility
Summary
by MITRE
An issue was discovered in atillk64.sys in AMD ATI Diagnostics Hardware Abstraction Sys/Overclocking Utility 5.11.9.0. The vulnerable driver exposes a wrmsr instruction 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 • 05/19/2020
The vulnerability identified as CVE-2019-7246 resides within the atillk64.sys driver component of AMD ATI Diagnostics Hardware Abstraction Sys/Overclocking Utility version 5.11.9.0. This driver operates at the kernel level and provides hardware abstraction services for AMD graphics processing units, specifically targeting the diagnostic and overclocking functionality of ATI graphics hardware. The issue manifests through improper handling of Model Specific Register (MSR) operations, creating a critical security flaw that affects system integrity and user security. The driver's exposure of the wrmsr instruction without adequate validation mechanisms represents a fundamental breakdown in kernel-mode security controls.
The technical flaw stems from the driver's failure to properly filter or validate Model Specific Register access operations. The wrmsr instruction allows direct write access to hardware registers that control various processor features including performance monitoring, power management, and security-related configurations. When this instruction is exposed without proper input validation or access controls, malicious actors can write arbitrary values to these sensitive registers. This vulnerability directly maps to CWE-787: "Out-of-bounds Write" and CWE-119: "Improper Restriction of Operations within the Bounds of a Memory Buffer" as it allows unauthorized memory access and manipulation of critical system registers. The lack of proper validation means that any user-level process can potentially invoke these privileged operations, effectively bypassing normal kernel-mode protection mechanisms.
The operational impact of this vulnerability is severe and encompasses complete system compromise. An attacker with local access can leverage this flaw to execute arbitrary code at Ring-0 privileges, effectively gaining full control over the target system. This privilege escalation allows for complete system takeover, enabling malicious activities such as persistent backdoor installation, data exfiltration, and further network reconnaissance. The vulnerability is particularly dangerous because it operates within the graphics driver context, which typically runs with high privileges and has direct hardware access. This makes it an ideal target for advanced persistent threats and privilege escalation attacks that align with ATT&CK technique T1055: "Process Injection" and T1068: "Exploitation for Privilege Escalation". The attack surface extends beyond simple code execution to include potential hardware-level manipulation that could affect system stability and security.
Mitigation strategies for CVE-2019-7246 must address both immediate remediation and long-term security hardening. The most effective immediate solution involves updating to the latest version of AMD ATI Diagnostics Hardware Abstraction Sys/Overclocking Utility, which includes proper MSR access validation and input filtering. System administrators should disable or remove the problematic driver component from systems where it is not required for legitimate operations. Additionally, implementing kernel-mode exploit protection mechanisms such as Control Flow Guard (CFG), Address Space Layout Randomization (ASLR), and Data Execution Prevention (DEP) can provide additional layers of defense. Network segmentation and privilege separation should be enforced to limit potential attack vectors, while monitoring systems should be configured to detect unusual MSR access patterns. The vulnerability highlights the importance of proper driver security practices and aligns with security frameworks that emphasize the principle of least privilege and secure coding practices for kernel-mode components.