CVE-2022-20416 in Android
Summary
by MITRE • 10/12/2022
In audioTransportsToHal of HidlUtils.cpp, there is a possible out of bounds write due to an incorrect bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12 Android-12L Android-13Android ID: A-237717857
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Analysis
by VulDB Data Team • 04/13/2026
The vulnerability identified as CVE-2022-20416 resides within the audioTransportsToHal function in the HidlUtils.cpp file of Android's hardware abstraction layer implementation. This flaw represents a critical security issue that affects Android 12, 12L, and 13 versions, where the system's audio transport handling mechanism contains a flawed bounds checking mechanism. The vulnerability manifests as an out-of-bounds write condition that occurs when processing audio transport data through the Hardware Abstraction Layer interface. The improper validation of array indices during the conversion process from audio transport parameters to hardware layer representations creates an opportunity for malicious code to write data beyond the allocated memory boundaries.
The technical nature of this vulnerability places it squarely within the category of buffer overflow conditions, specifically classified as CWE-129 in the Common Weakness Enumeration catalog. This type of flaw typically arises when software fails to properly validate input data ranges before using them as array indices or loop counters. The vulnerability's exploitation requires no user interaction, making it particularly dangerous as it can be triggered automatically through normal system operations. The flaw specifically impacts the audio subsystem's hardware abstraction layer where audio transport configuration data flows from the higher-level system services to the underlying hardware drivers. When the system processes audio transport parameters, the incorrect bounds check allows for an index value that exceeds the valid array boundaries, enabling arbitrary memory writes.
The operational impact of this vulnerability extends to a local privilege escalation scenario where an attacker with minimal privileges can potentially elevate their access level within the Android system. This represents a significant security risk as it allows for unauthorized access to system resources that would normally be restricted to privileged processes. The vulnerability's exploitation pathway involves manipulating audio transport parameters through legitimate system interfaces, which means that even standard applications or services could potentially trigger the condition. The attack surface is broadened by the fact that the audio subsystem is actively used across multiple applications and system services, increasing the likelihood of successful exploitation. The privilege escalation occurs because the out-of-bounds write can overwrite critical system data structures or function pointers, potentially allowing an attacker to execute arbitrary code with elevated privileges.
Mitigation strategies for CVE-2022-20416 should focus on immediate patch application from Google's security updates, which typically involve correcting the bounds checking logic in the HidlUtils.cpp file. Organizations should implement comprehensive monitoring for unusual audio subsystem behavior and system calls that might indicate exploitation attempts. The fix involves strengthening the validation logic to ensure that all array indices used in the audio transport conversion process are properly bounded against the actual array dimensions. System administrators should also consider implementing additional security controls such as runtime application whitelisting, process isolation for audio services, and memory protection mechanisms like stack canaries and address space layout randomization. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation through software vulnerabilities, specifically targeting the system's hardware abstraction layer to gain elevated access rights. Regular security assessments of system components and timely patch management remain critical defensive measures against such vulnerabilities.