CVE-2016-3811 in Android
Summary
by MITRE
The kernel video driver in Android before 2016-07-05 on Nexus 9 devices allows attackers to gain privileges via a crafted application, aka internal bug 28447556.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-3811 represents a critical privilege escalation flaw within the kernel video driver component of Android operating systems. This issue specifically affected Nexus 9 devices and was disclosed in the context of Android security updates released in July 2016. The vulnerability stems from inadequate input validation and access control mechanisms within the graphics subsystem, creating a pathway for malicious applications to execute code with elevated privileges. The flaw demonstrates the inherent risks associated with kernel-level components that handle multimedia processing and graphics rendering, particularly when these components fail to properly validate user-supplied data or enforce proper privilege boundaries.
The technical implementation of this vulnerability involves exploitation of the video driver's handling of malformed or crafted input data within the kernel space. Attackers could leverage this weakness by developing a malicious application that specifically targets the video driver's kernel interface, bypassing normal user-space security restrictions. The vulnerability operates at the kernel level where the privilege separation between user applications and system-level processes breaks down, allowing unauthorized code execution with root-level privileges. This type of flaw aligns with CWE-119, which addresses weaknesses in memory access and improper privilege handling in kernel modules, and represents a classic example of a kernel exploit that undermines the fundamental security model of the operating system.
The operational impact of CVE-2016-3811 extends beyond simple privilege escalation, as it fundamentally compromises the security architecture of affected Android devices. Once exploited, the vulnerability enables attackers to gain complete control over the device, potentially allowing for data theft, persistent backdoor installation, and complete system compromise. The affected Nexus 9 devices represent a significant portion of Android users at the time, making this vulnerability particularly dangerous from a threat perspective. The vulnerability's exploitation requires only a crafted application, meaning that users could be compromised through seemingly benign app downloads or even through social engineering attacks that trick users into installing malicious software. This attack vector aligns with ATT&CK technique T1068, which covers local privilege escalation through kernel exploits, and demonstrates how kernel-level vulnerabilities can be leveraged for comprehensive system compromise.
Mitigation strategies for this vulnerability required immediate system updates and patches provided by Google as part of their regular security update cycle. The fix involved strengthening input validation within the kernel video driver component and implementing proper privilege checks that prevent user-space applications from manipulating kernel-level graphics processing functions. Users were advised to install the July 2016 security patches, which included updates to the kernel components and enhanced memory management controls. Organizations deploying Android devices for enterprise use needed to implement robust patch management procedures to ensure timely deployment of security updates. The vulnerability also highlighted the importance of kernel hardening techniques and proper privilege separation mechanisms, reinforcing industry best practices for securing mobile operating system kernels against similar attacks. This case study serves as a reminder of the critical importance of kernel-level security and the potential consequences of inadequate privilege enforcement in system components that handle sensitive multimedia processing functions.