CVE-2022-20446 in Android
Summary
by MITRE • 11/09/2022
In AlwaysOnHotwordDetector of AlwaysOnHotwordDetector.java, there is a possible way to access the microphone from the background due to a missing permission 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-10 Android-11Android ID: A-229793943
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Analysis
by VulDB Data Team • 04/15/2026
The vulnerability identified as CVE-2022-20446 resides within the AlwaysOnHotwordDetector component of Android's system services, specifically in the AlwaysOnHotwordDetector.java file. This flaw represents a critical security weakness that allows unauthorized background microphone access through a missing permission check mechanism. The vulnerability affects Android versions 10 and 11, making it particularly concerning given the widespread deployment of these operating system versions across mobile devices. The issue stems from insufficient access controls within the hotword detection service that is designed to listen for voice commands even when the device is in standby mode, creating a potential attack vector for malicious actors seeking persistent audio surveillance capabilities.
The technical root cause of this vulnerability lies in the absence of proper permission validation within the AlwaysOnHotwordDetector service implementation. When the system processes hotword detection requests, it fails to verify whether the requesting component possesses the necessary audio recording permissions before granting microphone access. This missing permission check creates a privilege escalation path where any application or service running in the background can potentially access microphone data without explicit user consent or proper authorization. The flaw operates at the system level within Android's audio framework, specifically within the audio policy manager and audio recording subsystems. This type of vulnerability falls under CWE-284, which addresses improper access control issues, and more specifically aligns with CWE-352, concerning cross-site request forgery, though adapted to the mobile context. The vulnerability operates through the Android framework's binder IPC mechanism, where the hotword detection service communicates with various applications and system components without adequate authentication checks.
The operational impact of this vulnerability extends beyond simple privacy concerns to encompass potential full system compromise through local privilege escalation. Attackers can exploit this weakness to continuously monitor user conversations, capture sensitive information, and potentially gather intelligence for more sophisticated attacks. The vulnerability does not require user interaction for exploitation, making it particularly dangerous as it can be activated silently in the background without any visible indication to the user. This background access capability aligns with ATT&CK technique T1123, which describes the collection of audio data through microphone access, and T1068, which covers privilege escalation through local system vulnerabilities. The persistent nature of this access means that once exploited, attackers can maintain long-term surveillance capabilities without requiring additional privileges or user consent, effectively creating a covert surveillance mechanism that operates outside of normal application permissions.
Mitigation strategies for CVE-2022-20446 should focus on immediate system updates and enhanced permission validation mechanisms. Android security patches addressing this vulnerability typically involve implementing strict permission checks within the AlwaysOnHotwordDetector service to ensure that only authorized components can access microphone resources. Organizations should prioritize deploying the latest security updates from Google and device manufacturers as soon as available, as this vulnerability represents a significant risk to user privacy and device security. System administrators should also implement monitoring solutions to detect unauthorized microphone access patterns and consider network-level controls to prevent data exfiltration from compromised devices. The fix typically involves modifying the permission validation logic to check for proper audio recording permissions before granting access to the microphone, effectively closing the gap that allowed unauthorized background access. Additionally, device manufacturers should review their implementation of Android's audio framework to ensure proper isolation between system services and user applications, preventing similar issues in other components of the audio subsystem.