CVE-2023-20920 in Android
Summary
by MITRE • 01/26/2023
In queue of UsbRequest.java, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-12 Android-12L Android-13Android ID: A-204584366
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Analysis
by VulDB Data Team • 09/03/2025
The vulnerability identified as CVE-2023-20920 resides within the USB request queue implementation in Android's UsbRequest.java component, representing a critical memory corruption issue that can be exploited for privilege escalation. This flaw manifests as a use-after-free condition that occurs when the system attempts to access memory that has already been freed during USB request processing operations. The vulnerability affects multiple Android versions including Android 10 through Android 13, indicating a widespread impact across the platform's lifecycle. The use-after-free vulnerability falls under CWE-416, which specifically addresses the use of memory after it has been freed, making it a well-documented and dangerous class of memory safety issue.
The technical exploitation of this vulnerability occurs within the USB subsystem where the UsbRequest.java implementation manages asynchronous USB requests and their associated memory allocations. When a USB request completes and the system attempts to free the associated memory structures, a race condition or improper state management can lead to scenarios where subsequent operations attempt to access already-released memory regions. This memory corruption can manifest in various ways including stack corruption, heap corruption, or pointer manipulation that allows an attacker to potentially control execution flow. The vulnerability does not require user interaction for exploitation, making it particularly concerning as it can be triggered automatically during normal USB operations.
The operational impact of this vulnerability extends beyond simple memory corruption to enable local privilege escalation, allowing an attacker with minimal privileges to gain elevated system access. This escalation occurs because the memory corruption can be leveraged to manipulate kernel data structures or execute arbitrary code with system-level privileges. The attack vector operates entirely within the local environment without requiring additional execution privileges or user interaction, which significantly increases the exploitability and potential damage. This characteristic places the vulnerability in the ATT&CK framework under the privilege escalation technique category, specifically targeting local system access and kernel-level manipulation.
Mitigation strategies for CVE-2023-20920 should focus on immediate patch deployment through Android security updates, as the vulnerability represents a critical threat to system integrity. System administrators and device manufacturers must prioritize applying the relevant security patches that address the memory management issues in the USB request queue implementation. Additional protective measures include implementing proper memory validation checks, strengthening the USB subsystem's memory management routines, and potentially isolating USB operations through sandboxing mechanisms. The vulnerability highlights the importance of proper resource management in kernel-level components and underscores the need for comprehensive memory safety testing in mobile operating systems. Organizations should also monitor for potential exploitation attempts and implement network-based detection mechanisms to identify suspicious USB-related activities that might indicate exploitation attempts.