CVE-2020-0089 in Android
Summary
by MITRE
In the audio server, there is a missing permission check. This could lead to local escalation of privilege regarding audio settings with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-137015603
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Analysis
by VulDB Data Team • 09/18/2020
The vulnerability identified as CVE-2020-0089 resides within Android's audio server component, representing a critical permission bypass flaw that enables local privilege escalation. This issue affects Android 11 and demonstrates how insufficient access controls in system services can be exploited to gain elevated privileges without requiring additional execution capabilities or user interaction. The audio server in Android systems manages audio configuration settings and device audio routing, making it a prime target for attackers seeking to expand their system control. The vulnerability specifically manifests as a missing permission check that should validate whether processes attempting to modify audio settings possess the appropriate authorization levels.
The technical implementation of this flaw involves the audio server failing to properly validate the privileges of processes attempting to access or modify audio configuration parameters. When legitimate applications or system processes request audio setting changes, the server should verify that these operations originate from authorized entities with appropriate permissions. However, this validation mechanism is absent or improperly implemented, allowing unauthorized processes to execute privileged audio operations. The vulnerability falls under the CWE-284 access control weakness category, specifically addressing insufficient privilege checking within system services. This type of flaw represents a classic local privilege escalation vector where an attacker with basic user-level access can leverage the missing permission check to execute operations that should require elevated privileges.
The operational impact of CVE-2020-0089 extends beyond simple privilege escalation, as it provides attackers with potential access to sensitive audio system configurations and device audio routing capabilities. This could enable adversaries to manipulate audio outputs, redirect audio streams to unauthorized destinations, or potentially access audio input devices for surveillance purposes. The lack of user interaction requirement makes this vulnerability particularly concerning as it can be exploited automatically without requiring user engagement or specific attack vectors. Attackers could potentially use this privilege escalation to gain access to other system components that rely on audio subsystems, creating a foothold for further exploitation. The vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through system service manipulation.
Mitigation strategies for this vulnerability focus primarily on implementing proper permission validation within the audio server component and ensuring that all audio configuration operations require appropriate authorization checks. Android security patches addressing this issue typically involve strengthening the permission validation mechanisms within the audio server to verify process privileges before allowing audio setting modifications. System administrators should prioritize applying the latest security updates from Android vendors to remediate this vulnerability. Additionally, implementing runtime monitoring of audio server processes and their access patterns can help detect anomalous behavior that might indicate exploitation attempts. Organizations should also consider implementing application whitelisting policies and restricting unnecessary audio access permissions for applications that do not require audio system modifications. The vulnerability highlights the importance of comprehensive security testing for system services and the critical need for proper access control implementation in privileged components of mobile operating systems.