CVE-2016-8463 in Android
Summary
by MITRE
A denial of service vulnerability in the Qualcomm FUSE file system could enable a remote attacker to use a specially crafted file to cause a device hang or reboot. This issue is rated as High due to the possibility of remote denial of service. Product: Android. Versions: Kernel-3.10, Kernel-3.18. Android ID: A-30786860. References: QC-CR#586855.
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Analysis
by VulDB Data Team • 10/27/2022
The vulnerability described in CVE-2016-8463 represents a critical denial of service flaw within the Qualcomm FUSE (Filesystem in Userspace) implementation that affects Android devices running kernel versions 3.10 and 3.18. This vulnerability resides in the kernel-level file system handling mechanism and specifically targets the FUSE subsystem which allows userspace programs to implement their own file systems. The issue stems from inadequate input validation and error handling within the FUSE file system driver, creating a condition where malformed or specially crafted file structures can trigger unexpected behavior in the underlying kernel.
The technical exploitation of this vulnerability occurs when a remote attacker crafts a malicious file that, when processed by the FUSE file system, causes the kernel to enter an infinite loop or critical state that results in system instability. This flaw operates at the kernel level and leverages the FUSE framework's interaction with the Android kernel's file system management components. The vulnerability is particularly concerning because it can be triggered remotely through network-based file transfers or malicious file sharing scenarios, making it accessible to attackers without physical access to the device. The attack vector typically involves creating a file with specific characteristics that cause the FUSE subsystem to malfunction during file operations.
The operational impact of this vulnerability extends beyond simple system unavailability as it can cause complete device hang or forced reboot cycles that disrupt normal user operations and potentially create security concerns through service disruption. When exploited successfully, the vulnerability can render devices temporarily or permanently unusable until manual intervention or device reboot occurs. This type of denial of service attack can be particularly damaging in enterprise environments where device availability is critical, or in scenarios where devices are deployed in remote locations where physical access is limited. The vulnerability affects a wide range of Android devices that utilize Qualcomm chipsets and the associated kernel implementations, making it a widespread concern across multiple device manufacturers and models.
Mitigation strategies for this vulnerability should focus on kernel-level updates and patches provided by device manufacturers, as the flaw exists within the core operating system components. Organizations should prioritize applying security patches from their device vendors and ensure that all Android devices in their environment are updated to versions that contain the necessary fixes for the FUSE subsystem. Additionally, network administrators should consider implementing file filtering mechanisms to prevent potentially malicious files from reaching devices, particularly in environments where device security is paramount. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and may relate to ATT&CK technique T1499.001 for network denial of service attacks, though the specific implementation involves kernel-level exploitation rather than network-based disruption.
This vulnerability demonstrates the importance of proper input validation and error handling in kernel space components, as inadequate protection mechanisms can create exploitable conditions that affect entire device populations. The issue highlights the complexity of kernel-level security and the need for comprehensive testing of file system implementations, particularly those that provide userspace access to kernel functionality through FUSE frameworks. Device manufacturers and security researchers should continue monitoring for similar issues in kernel-based file systems and ensure that proper security controls are implemented to prevent unauthorized access to critical system resources through file system manipulation.