CVE-2016-6737 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the kernel ION subsystem in Android before 2016-11-05 could enable a local malicious application to execute arbitrary code within the context of the kernel. This issue is rated as Critical due to the possibility of a local permanent device compromise, which may require reflashing the operating system to repair the device. Android ID: A-30928456.
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Analysis
by VulDB Data Team • 09/30/2022
The vulnerability identified as CVE-2016-6737 represents a critical elevation of privilege flaw within the Android kernel's ION subsystem, a memory management component designed to facilitate efficient memory allocation and sharing between different system components. This vulnerability existed in Android versions prior to the 2016-11-05 security patch release and allowed local malicious applications to escalate their privileges to kernel level execution rights. The ION subsystem serves as a crucial interface for memory management in Android devices, handling buffer allocations and memory sharing operations between various kernel drivers and user-space applications. The flaw stems from improper input validation and memory management handling within this subsystem, creating a pathway for privilege escalation that could potentially compromise the entire device.
The technical nature of this vulnerability involves a memory corruption issue within the kernel's ION driver that occurs when processing certain memory allocation requests from user-space applications. Attackers could exploit this flaw by crafting malicious memory allocation requests that would cause the kernel to execute arbitrary code with elevated privileges. This type of vulnerability falls under the CWE-119 weakness category, which encompasses memory safety issues including buffer overflows and improper access to memory regions. The vulnerability operates at the kernel level, making it particularly dangerous as it bypasses standard user-space security mechanisms and allows direct access to sensitive kernel memory areas. The exploitation requires local access to the device, meaning an attacker must already have a malicious application installed on the target device, but once exploited, the consequences are severe enough to potentially require complete system reinstallation.
The operational impact of CVE-2016-6737 extends far beyond typical application-level security breaches, as it provides a pathway for permanent device compromise that could render the device unusable without extensive repair efforts. This vulnerability represents a significant threat to device integrity and user data security, as successful exploitation could enable attackers to gain complete control over the device's kernel operations. The attack surface is particularly concerning because the ION subsystem is widely used across Android devices for various memory management tasks, making this vulnerability potentially widespread across multiple device manufacturers and model lines. The severity classification as Critical by the Android security team reflects the potential for persistent compromise and the difficulty of remediation, as the vulnerability could be leveraged to install rootkits, modify system binaries, or completely disable security features. This type of vulnerability aligns with ATT&CK technique T1068, which describes the use of local privilege escalation to gain elevated system access, and demonstrates how kernel-level flaws can enable broader compromise scenarios.
Mitigation strategies for this vulnerability primarily involve applying the official Android security patches released on 2016-11-05, which included fixes for the ION subsystem memory management issues. Device manufacturers were required to incorporate these patches into their respective Android updates, and users needed to install the security updates to protect against exploitation. Additionally, system administrators and security professionals should implement monitoring for suspicious memory allocation patterns and ensure that all devices are kept up to date with the latest security patches. The vulnerability highlights the importance of kernel security testing and the need for comprehensive memory safety measures in operating system components. Organizations should also consider implementing device management policies that enforce automatic security updates and maintain inventory tracking of device security patch status to prevent exploitation of known vulnerabilities. The incident underscores the critical nature of maintaining up-to-date security patches and demonstrates how kernel-level vulnerabilities can have cascading effects on device security and user privacy.