CVE-2020-0484 in Android
Summary
by MITRE • 12/15/2020
In destroyResources of ComposerClient.h, there is possible memory corruption due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-155769496
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Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0484 resides within the Android operating system's composition engine component, specifically in the ComposerClient.h header file where the destroyResources function exhibits memory corruption behavior through use-after-free conditions. This flaw represents a critical security weakness that can be exploited to achieve local privilege escalation, potentially allowing an attacker to gain system-level execution privileges. The vulnerability manifests when the system attempts to free memory resources that are subsequently accessed, creating a scenario where malicious code can manipulate the freed memory locations to execute arbitrary commands with elevated privileges.
The technical implementation of this vulnerability stems from improper memory management practices within the Android graphics composition subsystem. When the destroyResources function processes resource cleanup operations, it fails to properly validate memory references before subsequent access operations, creating a window where freed memory blocks can be reallocated and accessed by unauthorized processes. This use-after-free condition falls under the common weakness enumeration CWE-416, which specifically addresses the use of freed memory in software applications. The flaw operates at the kernel level within Android's surfaceflinger component, which manages the display composition and rendering of graphical elements across the system.
The operational impact of CVE-2020-0484 extends beyond simple memory corruption, as it provides a pathway for local privilege escalation that can result in complete system compromise. Attackers exploiting this vulnerability can leverage the freed memory to overwrite critical system structures or inject malicious code that executes with system-level privileges, effectively bypassing Android's traditional security boundaries. The exploitation requires no user interaction, making it particularly dangerous as it can be triggered automatically during normal system operations or when graphics-intensive applications are running. This vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and specifically targets the Android system's privilege model through memory corruption attacks.
Mitigation strategies for this vulnerability require immediate system updates through official Android security patches that address the improper memory management in the ComposerClient.h file. Organizations should implement comprehensive patch management protocols to ensure all Android devices are updated with the latest security fixes from Google. Additional protective measures include monitoring system logs for unusual memory access patterns, implementing application sandboxing to limit potential exploitation scope, and conducting regular security assessments of graphics processing components. The vulnerability demonstrates the critical importance of proper memory management in operating system kernels, particularly in components handling graphical resources where memory corruption can directly translate to privilege escalation capabilities. System administrators should prioritize patch deployment and consider implementing network segmentation to limit potential attack vectors while awaiting full system updates.