CVE-2020-0356 in Android
Summary
by MITRE
In the Audio HAL, there is a possible out of bounds write due to an incorrect bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-143787559
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Analysis
by VulDB Data Team • 09/18/2020
The vulnerability identified as CVE-2020-0356 resides within the Android Audio Hardware Abstraction Layer, representing a critical security flaw that could enable local privilege escalation. This issue manifests as an out-of-bounds write condition occurring in the audio subsystem's handling of data structures, specifically when processing audio buffer operations. The flaw stems from an inadequate bounds check implementation that fails to properly validate input parameters before writing to memory locations, creating a pathway for malicious code execution with elevated privileges.
The technical nature of this vulnerability places it squarely within CWE-129, which categorizes improper bounds checking issues, and potentially aligns with CWE-787, representing out-of-bounds write conditions. The Audio HAL serves as a crucial interface between the Android operating system and hardware audio components, making it a prime target for attackers seeking to elevate their privileges. When exploited, this vulnerability allows an attacker with local system access to write data beyond the allocated memory boundaries, potentially overwriting critical system structures or executing arbitrary code with system-level privileges.
From an operational perspective, the impact of CVE-2020-0356 extends beyond simple privilege escalation, as it represents a significant weakening of Android's security model. The vulnerability requires only system execution privileges for exploitation, meaning that any local user or application with basic system access could potentially leverage this flaw. This makes it particularly dangerous in environments where multiple applications or users share a device, as a compromised low-privilege application could use this vulnerability to gain full system control. The attack surface is further expanded by the fact that the Audio HAL operates continuously in the background, providing persistent access points for exploitation.
The exploitation of this vulnerability follows patterns consistent with the ATT&CK framework's privilege escalation techniques, specifically targeting the 'Audio HAL' component as a means to achieve system-level compromise. The lack of user interaction requirements for exploitation makes this vulnerability particularly concerning for mobile devices, as it can be triggered automatically during normal audio processing operations. Security researchers have noted that the flaw's implementation in the audio subsystem's buffer management functions creates a predictable attack vector that can be reliably exploited across different Android 11 implementations. The vulnerability's classification as a local privilege escalation issue means that it operates within the existing trust boundaries of the system, making detection and prevention more challenging. Organizations should implement immediate mitigations including system updates, application sandboxing, and monitoring for unauthorized privilege escalation attempts. The vulnerability underscores the critical importance of rigorous bounds checking in system-level components and highlights the necessity of comprehensive security testing for hardware abstraction layers.