CVE-2020-6101 in Radeon DirectX 11 Driver
Summary
by MITRE
An exploitable code execution vulnerability exists in the Shader functionality of AMD Radeon DirectX 11 Driver atidxx64.dll 26.20.15019.19000. An attacker can provide a specially crafted shader file to trigger this vulnerability, resulting in code execution. This vulnerability can be triggered from a HYPER-V guest using the RemoteFX feature, leading to executing the vulnerable code on the HYPER-V host (inside of the rdvgm.exe process). Theoretically this vulnerability could be also triggered from web browser (using webGL and webassembly).
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Analysis
by VulDB Data Team • 07/21/2020
The vulnerability identified as CVE-2020-6101 represents a critical code execution flaw within the AMD Radeon DirectX 11 driver component atidxx64.dll version 26.20.15019.19000. This issue resides in the shader processing functionality of the graphics driver, which is responsible for handling graphical computations and rendering operations in DirectX 11 environments. The vulnerability stems from inadequate input validation and memory management within the shader handling code, creating a potential attack surface that could be exploited by malicious actors to execute arbitrary code on affected systems.
The technical exploitation of this vulnerability occurs through the manipulation of shader files that are processed by the graphics driver. When a specially crafted shader file is loaded and executed by the vulnerable driver component, the improper memory handling allows attackers to overwrite critical memory regions or execute malicious code within the driver context. This flaw operates at the kernel level within the graphics driver, making it particularly dangerous as it can bypass standard user-mode security controls and directly impact system integrity. The vulnerability specifically affects the HYPER-V environment where RemoteFX graphics acceleration is utilized, creating a unique attack vector that can be leveraged to escalate privileges from guest virtual machines to the host system.
The operational impact of this vulnerability extends beyond simple code execution, as it creates a potential pathway for privilege escalation attacks within virtualized environments. When exploited through HYPER-V guest systems using RemoteFX, the vulnerability allows attackers to execute code within the rdvgm.exe process on the host system, effectively breaking the isolation boundary between virtual machines and the host infrastructure. This scenario represents a significant concern for cloud service providers and organizations relying on virtualization technologies, as it could enable attackers to compromise entire host systems from within compromised guest environments. The theoretical web browser exploitation through WebGL and WebAssembly further expands the attack surface, potentially allowing remote code execution through standard web browsing activities without requiring specialized privileges or local access.
Mitigation strategies for CVE-2020-6101 should prioritize immediate driver updates from AMD to address the underlying memory handling issues in the atidxx64.dll component. Organizations should implement network segmentation and access controls to limit exposure of systems running vulnerable graphics drivers, particularly in virtualized environments where the HYPER-V attack vector is applicable. Security configurations should include disabling unnecessary graphics acceleration features when not required, especially in web browsing contexts where WebGL and WebAssembly execution could be exploited. The vulnerability aligns with CWE-121 and CWE-122 categories related to improper restriction of operations within a recognized security boundary, and maps to ATT&CK techniques involving privilege escalation and defense evasion through driver-level exploits. System administrators should monitor for suspicious process activity related to graphics drivers and implement endpoint detection and response solutions capable of identifying anomalous shader processing behaviors that could indicate exploitation attempts.