CVE-2019-2186 in Android
Summary
by MITRE
In GetMBheader of combined_decode.cpp, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9 Android-10Android ID: A-136175447
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Analysis
by VulDB Data Team • 10/03/2020
The vulnerability identified as CVE-2019-2186 represents a critical out-of-bounds write flaw within the Android media framework's combined_decode.cpp component. This issue resides in the GetMBheader function where proper bounds checking mechanisms are absent, creating a scenario where maliciously crafted media files could trigger memory corruption. The vulnerability affects multiple Android versions including 7.1.1, 7.1.2, 8.0, 8.1, 9, and 10, indicating a widespread impact across the Android ecosystem. The flaw is particularly concerning because it enables remote code execution without requiring any additional privileges beyond what is normally available to a user. This means an attacker could exploit the vulnerability through network-based attacks or by tricking users into opening malicious media content, making it a significant threat vector for mobile device security.
The technical nature of this vulnerability aligns with CWE-787, which specifically addresses out-of-bounds write conditions in software systems. The flaw occurs during the processing of media headers where the application fails to validate the boundaries of memory allocations before writing data. This missing bounds check allows attackers to write data beyond the allocated memory buffer, potentially overwriting adjacent memory locations and corrupting program execution flow. The vulnerability's exploitation requires user interaction, typically through opening malicious media files, but once triggered, it can provide complete system compromise. The attack surface is broad as it affects the core media processing capabilities of Android devices, making it particularly dangerous for both personal and enterprise environments where media consumption is common.
From an operational impact perspective, this vulnerability creates a serious risk for Android users and organizations relying on mobile device security. The remote code execution capability means attackers could potentially install malware, access sensitive data, or take full control of affected devices without requiring physical access or elevated privileges. The fact that user interaction is needed for exploitation suggests that social engineering attacks could be particularly effective, as users might unknowingly open malicious media files from email attachments, messaging apps, or downloaded content. Organizations should be particularly concerned about the widespread impact across multiple Android versions, as patch management becomes complex when dealing with such a broad range of affected systems. The vulnerability also represents a significant concern for the ATT&CK framework's execution and privilege escalation tactics, as it could enable attackers to establish persistent access to devices through media-based attack vectors.
The recommended mitigations for CVE-2019-2186 include immediate deployment of security patches provided by Google for affected Android versions, as well as implementing network-based controls to filter potentially malicious media content. Organizations should consider deploying mobile device management solutions that can enforce security policies and ensure timely patch deployment across all devices. Additional protective measures include user education about the risks of opening unknown media files, network monitoring for suspicious file transfers, and implementing application whitelisting where possible. The vulnerability highlights the importance of rigorous input validation and bounds checking in media processing libraries, as these components are frequently targeted by attackers due to their exposure to untrusted data. Security teams should also monitor for exploitation attempts and implement incident response procedures specifically designed for mobile device compromise scenarios.