CVE-2023-5091 in Valhall GPU Kernel Driver
Summary
by MITRE • 01/08/2024
Use After Free vulnerability in Arm Ltd Valhall GPU Kernel Driver allows a local non-privileged user to make improper GPU processing operations to gain access to already freed memory. This issue affects Valhall GPU Kernel Driver: from r37p0 through r40p0.
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Analysis
by VulDB Data Team • 01/25/2024
The CVE-2023-5091 vulnerability represents a critical use-after-free condition within the Arm Ltd Valhall GPU Kernel Driver, specifically impacting versions ranging from r37p0 through r40p0. This flaw resides in the kernel-level graphics processing subsystem that manages GPU operations for Arm-based mobile and embedded devices. The vulnerability arises when the driver fails to properly manage memory references during GPU command processing, creating a window where freed memory regions can be accessed and manipulated by malicious processes. Such a condition fundamentally compromises the memory safety mechanisms that protect kernel space operations from unauthorized access.
The technical exploitation of this vulnerability occurs when a local non-privileged user leverages improper GPU processing operations to trigger the use-after-free scenario. During normal GPU command execution, the kernel driver allocates memory structures to handle graphics processing tasks, but fails to properly invalidate references when these structures are freed. This creates a race condition where subsequent GPU operations can reuse the freed memory address space, allowing attackers to either corrupt existing data structures or inject malicious code into the kernel memory space. The vulnerability is particularly dangerous because it operates at kernel level within the GPU driver, bypassing standard user-space security controls and memory protection mechanisms that typically safeguard against such attacks.
From an operational impact perspective, this vulnerability enables a local attacker to escalate privileges from user-level to kernel-level access, potentially compromising the entire system integrity. The attack vector requires local access to the device but does not necessitate elevated privileges, making it particularly concerning for mobile devices where users may have limited security awareness. Successful exploitation could lead to complete system compromise, data exfiltration, persistent backdoor installation, and potential denial of service conditions that affect GPU functionality and overall device performance. The affected range of driver versions suggests this vulnerability has been present for multiple releases, indicating a prolonged window of exposure for affected systems.
The vulnerability aligns with CWE-416, which specifically addresses the use of freed memory conditions in software systems, and demonstrates characteristics consistent with ATT&CK technique T1068, which involves local privilege escalation through kernel exploits. Security professionals should prioritize patching affected systems immediately, as the vulnerability provides a direct path to kernel-level compromise without requiring network connectivity or complex attack chains. Mitigation strategies should include implementing kernel memory protection features such as kernel address space layout randomization and controlling GPU driver access through proper user permissions. Organizations should also monitor for suspicious GPU processing activities and maintain comprehensive system logging to detect potential exploitation attempts. The vulnerability underscores the critical importance of kernel-level memory management in graphics processing units and highlights the need for robust security testing of embedded driver components in mobile and IoT environments.