CVE-2016-3818 in Android
Summary
by MITRE
libc in Android 4.x before 4.4.4 allows remote attackers to cause a denial of service (device hang or reboot) via a crafted file, aka internal bug 28740702.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-3818 resides within the standard C library implementation used in Android operating systems versions 4.x prior to 4.4.4. This flaw represents a critical security weakness that enables remote attackers to execute denial of service attacks against affected devices through the manipulation of crafted files. The vulnerability was internally tracked as bug 28740702, indicating its recognition within Google's internal security tracking systems. The issue stems from improper handling of specific file formats within the libc library functions that process file operations, creating a pathway for malicious actors to exploit the system's file parsing mechanisms.
The technical root cause of this vulnerability lies in inadequate input validation and error handling within the libc library's file processing routines. When the system encounters a specially crafted file that triggers specific parsing conditions, the library fails to properly manage the execution flow, leading to system instability. This flaw operates at the kernel level within the Android system's file handling infrastructure, where the libc functions interact with the underlying file system operations. The vulnerability specifically targets the way the library processes malformed or specially constructed file data, causing the system to enter an unrecoverable state that results in either device hang or complete system reboot. The exploitation mechanism leverages the predictable nature of file parsing routines to force the system into a crash condition through carefully constructed input data.
The operational impact of CVE-2016-3818 extends beyond simple service disruption as it can affect the availability and reliability of Android devices running vulnerable software versions. This vulnerability affects a significant portion of Android 4.x devices, particularly those running versions prior to 4.4.4, which were widely deployed across various manufacturers and device models. The remote nature of the attack means that adversaries can exploit this weakness without requiring physical access to the device, potentially enabling large-scale denial of service campaigns. The consequences include complete device unavailability, requiring manual reboot or power cycle to restore functionality, which can be particularly problematic in enterprise environments or IoT deployments where continuous availability is critical. Organizations and end users face the risk of service interruptions that can be either temporary or require significant recovery time, impacting productivity and user experience.
Mitigation strategies for this vulnerability focus on immediate system updates and patches to the Android operating system. The most effective solution involves upgrading to Android 4.4.4 or later versions where the vulnerability has been addressed through improved input validation and error handling mechanisms within the libc library. System administrators should implement comprehensive patch management protocols to ensure all affected devices receive the necessary security updates. Additionally, network-level monitoring and intrusion detection systems can help identify potential exploitation attempts by monitoring for unusual file access patterns or malformed file transfers. The vulnerability aligns with CWE-129, which addresses issues related to insufficient input validation, and represents a specific instance of how improper handling of external data can lead to system instability. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service attacks, demonstrating how file-based exploitation can be leveraged to achieve system availability compromise. Organizations should also consider implementing file validation policies and restricting access to potentially malicious file types until full patch coverage is achieved across their device fleets.