CVE-2018-5831 in Android
Summary
by MITRE
In the KGSL driver in Android releases from CAF using the linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-06-05, a reference counting error can lead to a Use After Free condition.
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Analysis
by VulDB Data Team • 04/05/2023
The vulnerability identified as CVE-2018-5831 represents a critical reference counting error within the KGSL (Kernel Graphics Subsystem) driver component of Android systems developed by Code Aurora Forum. This flaw exists in Linux kernel implementations across various Android variants including MSM-based Android, Firefox OS for MSM, and QRD Android platforms. The vulnerability manifests specifically in systems running before the security patch level dated June 5, 2018, making it a widespread concern affecting numerous devices that rely on Qualcomm's graphics processing capabilities.
The technical nature of this vulnerability stems from improper reference counting mechanisms within the KGSL driver's memory management subsystem. When the driver handles graphics memory allocations and deallocations, it fails to maintain accurate reference counts for kernel objects, leading to a scenario where memory that should remain allocated becomes freed prematurely. This mismanagement creates a Use After Free condition where an attacker can manipulate the system to access memory that has already been deallocated, potentially allowing for arbitrary code execution within kernel space.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides potential attackers with a pathway to escalate privileges within the Android operating system. The KGSL driver operates at kernel level and manages graphics processing unit resources, making it a prime target for exploitation. When a Use After Free condition occurs in this critical subsystem, it can enable attackers to execute malicious code with the highest system privileges, potentially leading to complete system compromise. The vulnerability affects not just individual applications but the entire operating system kernel, making it particularly dangerous in mobile environments where users expect robust security boundaries.
Mitigation strategies for CVE-2018-5831 primarily focus on applying the relevant security patches released by device manufacturers and the Android security team. Organizations and individuals should ensure their systems receive the June 2018 security updates that specifically address this reference counting error. Additionally, implementing kernel memory protection mechanisms such as kernel address space layout randomization and stack canaries can provide additional defense-in-depth measures. The vulnerability aligns with CWE-415 which describes improper handling of reference counts leading to double-free conditions, and may map to ATT&CK technique T1068 which covers privilege escalation through kernel exploits. Device manufacturers should also consider implementing robust code review processes focused on kernel memory management and reference counting to prevent similar issues in future implementations.