CVE-2016-3806 in Android
Summary
by MITRE
The MediaTek display driver in Android before 2016-07-05 on Android One devices allows attackers to gain privileges via a crafted application, aka Android internal bug 28402341 and MediaTek internal bug ALPS02715341.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability described in CVE-2016-3806 represents a critical privilege escalation flaw within the MediaTek display driver component of Android operating systems. This issue specifically affected Android One devices and remained unpatched until July 5th 2016, creating a significant window of exposure for millions of users. The vulnerability stems from improper input validation and memory management within the display driver subsystem, which operates at a privileged kernel level and handles graphics rendering operations for the device's display hardware.
The technical implementation of this flaw involves a kernel-level privilege escalation vulnerability that allows a malicious application with standard user privileges to execute arbitrary code with kernel-level permissions. This occurs through improper handling of display driver IOCTL (input/output control) commands that are designed to communicate between user-space applications and the kernel-space display driver. Attackers can craft a specially designed application that sends malformed or specially constructed IOCTL commands to the display driver, which then processes these commands without adequate validation, leading to memory corruption and privilege escalation.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with complete control over affected devices. Once exploited, the malicious application can access all device resources, read sensitive data from memory, modify system files, install additional malware, and potentially create persistent backdoors. This vulnerability directly violates the principle of least privilege and undermines the core security model of Android, which relies on strict separation between user applications and system-level components. The flaw affects the integrity and confidentiality of user data, as well as the availability of the device itself.
The vulnerability aligns with CWE-119 Improper Access to Memory and CWE-264 Permissions, Privileges, and Access Controls, both of which are fundamental to secure software development practices. From an ATT&CK framework perspective, this vulnerability maps to T1068 Exploitation for Privilege Escalation and T1059 Command and Scripting Interpreter, as attackers can leverage the privilege escalation to execute arbitrary commands with system-level privileges. The attack surface is particularly concerning for Android One devices, which were designed to provide a clean, stock Android experience but became vulnerable due to this kernel-level flaw. The vulnerability demonstrates the critical importance of secure driver development practices and proper input validation in kernel components, as these elements form the foundation of operating system security. Device manufacturers and security researchers should prioritize patch management and continuous monitoring of such vulnerabilities to maintain the security posture of mobile devices.
This vulnerability highlights the broader challenge of securing embedded systems and hardware drivers within mobile operating systems. The MediaTek display driver's privileged access to graphics hardware creates a high-value target for attackers, as successful exploitation provides access to a wide range of system resources. The vulnerability's existence underscores the need for comprehensive security testing of kernel modules and the implementation of robust input validation mechanisms. Organizations should implement regular security assessments of their device firmware and ensure timely deployment of security patches to protect against similar vulnerabilities in the future.