CVE-2016-3773 in Android
Summary
by MITRE
The MediaTek drivers in Android before 2016-07-05 on Android One devices allow attackers to gain privileges via a crafted application, aka Android internal bug 29008363 and MediaTek internal bug ALPS02703102.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-3773 represents a critical privilege escalation flaw within the MediaTek driver implementations found in Android operating systems prior to July 5th, 2016. This issue specifically affected Android One devices and stemmed from insufficient input validation and improper access control mechanisms within the MediaTek hardware abstraction layer drivers. The vulnerability was catalogued under Android internal bug 29008363 and MediaTek internal bug ALPS02703102, indicating its origin within the proprietary driver code that interfaces between the Android operating system and MediaTek's hardware components. The flaw allowed malicious applications to exploit kernel-level privileges through carefully crafted payloads that manipulated driver interfaces.
The technical exploitation of this vulnerability occurs through improper validation of user-supplied data within the MediaTek driver code, creating a path for privilege escalation from user-space applications to kernel-level execution. This type of flaw falls under CWE-121, which describes buffer overflow conditions that can lead to privilege escalation, and more specifically aligns with CWE-264, which addresses permissions, privileges, and access controls. Attackers could leverage this vulnerability by installing a malicious application that would trigger specific driver functions, potentially allowing them to execute arbitrary code with kernel-level privileges. The attack vector typically involves exploiting memory corruption vulnerabilities within the driver's handling of device ioctls or other communication mechanisms between user-space processes and kernel drivers.
The operational impact of CVE-2016-3773 was severe across the affected Android One device ecosystem, as it enabled attackers to bypass the standard Android security model and gain root access to vulnerable devices. This privilege escalation capability meant that malicious applications could access all device data, modify system files, install persistent backdoors, and potentially compromise the entire device security posture. The vulnerability was particularly concerning because it affected devices that were marketed as secure and user-friendly, undermining the trust users placed in the Android One platform. Devices running Android versions before the July 2016 security patch were at risk, with the vulnerability remaining exploitable until the release of the corresponding security updates from Google and MediaTek.
Mitigation strategies for CVE-2016-3773 required immediate application of security patches released by Google as part of the Android security bulletin for July 2016, which included updated MediaTek driver implementations and kernel-level fixes. Organizations and device manufacturers needed to ensure prompt deployment of these patches across affected Android One devices, particularly those still in use in enterprise environments or consumer markets. The vulnerability highlighted the importance of proper driver security testing and code review processes, as it demonstrated how flaws in proprietary hardware drivers could create persistent security risks. System administrators should have implemented device management policies to ensure all affected devices received the necessary updates, while security researchers recommended monitoring for exploitation attempts through network traffic analysis and behavioral monitoring systems. This vulnerability also underscored the need for comprehensive security testing of hardware abstraction layers and the importance of maintaining up-to-date security patches across all device components, as documented in the ATT&CK framework's privilege escalation techniques and the broader concept of kernel-mode exploitation within mobile device security.