CVE-2016-8434 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the Qualcomm GPU driver 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. Product: Android. Versions: Kernel-3.10. Android ID: A-32125137. References: QC-CR#1081855.
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Analysis
by VulDB Data Team • 10/27/2022
The vulnerability identified as CVE-2016-8434 represents a critical elevation of privilege flaw within the Qualcomm GPU driver component of Android systems running kernel version 3.10. This issue stems from improper input validation and memory management within the graphics processing unit driver, creating a pathway for local malicious applications to escalate their privileges and gain kernel-level execution capabilities. The vulnerability specifically affects devices where the Qualcomm GPU driver fails to properly validate buffer sizes and memory access patterns during graphics command processing, allowing crafted malicious code to manipulate kernel memory structures and execute arbitrary code with the highest system privileges.
The technical exploitation of this vulnerability occurs through a buffer overflow or memory corruption issue within the GPU driver's command processing mechanism. When a malicious application submits specially crafted graphics commands or buffer operations to the GPU driver, the insufficient validation allows the attacker to overwrite kernel memory locations, potentially including function pointers or return addresses. This memory corruption enables the execution of arbitrary code within the kernel context, bypassing standard security boundaries and allowing persistent control over the device. The flaw is classified as a CWE-121 stack-based buffer overflow or similar memory corruption vulnerability, representing a fundamental breakdown in the driver's input sanitization mechanisms. The ATT&CK framework categorizes this as privilege escalation through kernel exploits, specifically targeting the 'Exploitation for Privilege Escalation' technique under the privilege escalation tactic.
The operational impact of CVE-2016-8434 extends far beyond simple local code execution, as it provides attackers with complete kernel-level access that can lead to permanent device compromise. Once successfully exploited, the malicious application can modify critical system files, install rootkits, disable security features, and maintain persistence across reboots. The vulnerability's critical rating reflects the potential for complete system takeover, requiring users to perform full device reflash operations to restore proper functionality. This makes the exploit particularly dangerous in environments where devices are not regularly updated or where users cannot easily access recovery modes. The affected Android systems running kernel 3.10 are particularly vulnerable because this kernel version had known memory management issues within the Qualcomm GPU driver implementation, creating multiple attack vectors for privilege escalation.
Mitigation strategies for CVE-2016-8434 focus primarily on updating the affected Qualcomm GPU driver components and applying the relevant Android security patches. Device manufacturers and carriers should prioritize immediate deployment of kernel updates that address the memory corruption issues within the GPU driver, particularly those that implement proper buffer size validation and memory access controls. System administrators should disable unnecessary GPU driver features and implement application whitelisting to prevent malicious applications from submitting harmful graphics commands. The implementation of kernel address space layout randomization and other exploit mitigations can help reduce the effectiveness of potential exploitation attempts. Additionally, regular security audits of graphics driver components and continuous monitoring for similar vulnerabilities in other driver subsystems should be implemented to prevent future incidents. Organizations should also consider device lockdown procedures and secure boot mechanisms to prevent unauthorized kernel modifications that could be leveraged to exploit this vulnerability.