CVE-2021-0484 in Android
Summary
by MITRE • 06/11/2021
In readVector of IMediaPlayer.cpp, there is a possible read of uninitialized heap data due to a missing bounds check. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-9 Android-10 Android-11 Android-8.1Android ID: A-173720767
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Analysis
by VulDB Data Team • 06/14/2021
The vulnerability identified as CVE-2021-0484 resides within the Android media playback subsystem, specifically in the IMediaPlayer.cpp file where the readVector function processes data structures. This issue represents a classic case of uninitialized memory access that occurs when the system fails to validate bounds before reading heap-allocated data. The flaw manifests when the media player component attempts to parse vector data structures without proper validation of array boundaries, creating a scenario where uninitialized memory segments could be read and potentially exposed to unauthorized access.
The technical implementation of this vulnerability stems from insufficient input validation within the media player's data processing pipeline. When the readVector function handles incoming data streams, it does not perform adequate bounds checking to ensure that memory access operations remain within allocated buffer limits. This missing validation allows for potential reads beyond the intended data boundaries, resulting in the exposure of uninitialized heap data that may contain residual information from previous operations. The vulnerability is categorized under CWE-457 as "Use of Uninitialized Variable" and represents a memory safety issue that affects the integrity of data handling within the Android media framework.
The operational impact of CVE-2021-0484 extends beyond simple information disclosure, as it provides adversaries with access to potentially sensitive data that may have been stored in uninitialized memory regions. This information disclosure occurs without requiring any special privileges or user interaction, making the vulnerability particularly concerning for mobile environments where applications have broad access to system resources. The affected Android versions span multiple releases including Android 8.1, 9, 10, and 11, indicating a widespread exposure across the Android ecosystem. Attackers could potentially leverage this vulnerability to extract sensitive information that may include remnants of previous media processing operations, system state data, or other confidential information stored in memory.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript" and T1566.001 for "Phishing: Spearphishing Attachment" as it could be exploited through media file delivery mechanisms. The lack of user interaction requirements and minimal privilege needs make this vulnerability particularly attractive for automated exploitation campaigns. Security practitioners should consider this issue as part of broader memory safety assessments and implement comprehensive monitoring for unusual data access patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of bounds checking in memory management operations and demonstrates how seemingly minor validation gaps can lead to significant information disclosure risks in mobile operating systems.
Mitigation strategies should focus on implementing proper bounds checking mechanisms within the media player's data processing functions and ensuring that all heap-allocated memory is properly initialized before use. Android security updates typically address such issues through patches that enforce stricter validation protocols and memory access controls. Organizations should prioritize applying the latest security patches from Google and maintain comprehensive monitoring of system logs for any anomalous data access patterns that might indicate exploitation attempts. The vulnerability also underscores the necessity of adopting secure coding practices and conducting regular security reviews of core system components to identify and remediate similar memory safety issues before they can be exploited in the wild.