CVE-2016-6704 in Android
Summary
by MITRE
An elevation of privilege vulnerability in Mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, 6.x before 2016-11-01, and 7.0 before 2016-11-01 could enable a local malicious application to execute arbitrary code within the context of a privileged process. This issue is rated as High because it could be used to gain local access to elevated capabilities, which are not normally accessible to a third-party application. Android ID: A-30229821.
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Analysis
by VulDB Data Team • 09/30/2022
The vulnerability identified as CVE-2016-6704 represents a critical elevation of privilege flaw within the Android Mediaserver component, affecting multiple versions of the Android operating system from 4.x through 7.0. This vulnerability resides in the media processing subsystem that handles multimedia file operations and is particularly concerning due to its potential to allow local malicious applications to execute arbitrary code with elevated privileges. The Mediaserver process operates with significant system-level permissions, making any compromise of this component a severe threat to overall system security. The vulnerability was assigned a high severity rating by Android security teams due to the potential for unauthorized access to privileged system capabilities that should normally be restricted from third-party applications.
The technical flaw manifests in how the Mediaserver component processes certain multimedia files, specifically through improper input validation and memory handling during media decoding operations. Attackers can exploit this weakness by crafting malicious media files or manipulating existing media content to trigger buffer overflows or other memory corruption issues within the privileged Mediaserver process. This allows a local malicious application to escalate its privileges and execute code with the same elevated permissions as the system-level Mediaserver service. The vulnerability stems from inadequate bounds checking and memory management practices within the media processing pipeline, creating exploitable conditions that bypass normal Android security boundaries. The flaw is categorized under CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through local system exploitation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with access to sensitive system resources and capabilities that are normally protected from third-party applications. Once successfully exploited, the malicious application could access system files, modify core Android components, intercept communications, and potentially establish persistent backdoors within the device. This vulnerability affects the fundamental security model of Android by undermining the isolation between user applications and system services, effectively allowing local code execution with system-level privileges. The risk is particularly significant for devices where users may install untrusted applications or where applications have been compromised through other attack vectors, as the vulnerability could be leveraged to gain complete system control. The impact affects a broad range of Android versions, making it a widespread concern for organizations and individuals using affected devices.
Mitigation strategies for CVE-2016-6704 primarily focus on applying the relevant security patches provided by Google and device manufacturers. Users should ensure their Android devices are updated to versions that include the fix, specifically Android 4.4.4, 5.0.2, 5.1.1, and the corresponding security updates for Android 6.0 and 7.0 releases. Device manufacturers are advised to implement the security patches promptly and ensure comprehensive testing to prevent regression issues. Additional protective measures include implementing application whitelisting policies, monitoring for unusual media processing activities, and maintaining regular security audits of installed applications. Network administrators should also consider deploying mobile device management solutions that can enforce security policies and restrict potentially malicious applications from gaining access to system-level resources. Organizations should conduct vulnerability assessments to identify affected devices and prioritize remediation efforts, particularly for devices that handle sensitive information or operate in high-security environments where the risk of exploitation could be particularly damaging.