CVE-2022-20561 in Android
Summary
by MITRE • 12/16/2022
In TBD of aud_hal_tunnel.c, there is a possible memory corruption 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 kernelAndroid ID: A-222162870References: N/A
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2022-20561 represents a critical memory corruption issue within the Android kernel's audio hardware abstraction layer tunnel implementation. This flaw exists in the aud_hal_tunnel.c file where a use after free condition can occur, fundamentally compromising the system's memory integrity. The vulnerability falls under the category of memory safety issues that are particularly dangerous in kernel space contexts where improper memory management can lead to severe system instability and privilege escalation.
The technical implementation of this vulnerability stems from improper handling of memory allocation and deallocation within the audio hardware abstraction layer. When the system processes audio tunneling operations, specific code paths in aud_hal_tunnel.c fail to properly validate memory references after deallocation, creating a window where freed memory locations can be accessed or overwritten. This use after free scenario occurs when the kernel attempts to reference a memory block that has already been freed, potentially allowing malicious code to manipulate the freed memory contents or redirect execution flow. The vulnerability is classified as a CWE-416 Use After Free condition, which directly maps to the memory corruption patterns observed in kernel-level exploits.
The operational impact of CVE-2022-20561 extends beyond typical memory corruption consequences, as it enables local privilege escalation without requiring any additional execution privileges or user interaction. This means that an attacker with local access to an Android device can exploit this vulnerability to gain elevated privileges within the kernel space, potentially achieving complete system compromise. The absence of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited automatically during normal device operation. The exploitability factor is further enhanced by the fact that the vulnerability exists within core kernel components that are actively utilized during audio processing operations, providing multiple potential attack vectors.
From a security framework perspective, this vulnerability demonstrates characteristics that align with ATT&CK technique T1068, which covers the exploitation of local privilege escalation vulnerabilities. The Android kernel's audio subsystem serves as a prime target for such attacks due to its privileged execution context and the frequency with which audio operations occur. The vulnerability's presence in the aud_hal_tunnel.c file indicates that the audio hardware abstraction layer lacks proper memory management controls, which is particularly concerning given that audio processing is a fundamental system function that occurs continuously. The Android ID A-222162870 confirms the vulnerability's classification within Google's security tracking system, emphasizing its significance in the Android security ecosystem. Mitigation strategies should focus on implementing proper memory validation checks, adding reference counting mechanisms, and ensuring that all memory operations within kernel space audio components follow secure coding practices that prevent use after free conditions.