CVE-2016-5857 in Android
Summary
by MITRE
The Qualcomm SPCom driver in Android before 7.0 allows local users to execute arbitrary code within the context of the kernel via a crafted application, aka Android internal bug 34386529 and Qualcomm internal bug CR#1094140.
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Analysis
by VulDB Data Team • 09/10/2020
The vulnerability identified as CVE-2016-5857 represents a critical privilege escalation flaw within the Qualcomm SPCom driver component of Android systems prior to version 7.0. This driver serves as a communication interface between user-space applications and kernel-level services, specifically handling secure communication protocols for Qualcomm-based devices. The vulnerability arises from insufficient input validation and improper memory management within the driver's kernel-space implementation, creating a pathway for malicious applications to escalate their privileges and gain direct kernel-level access.
The technical exploitation of this vulnerability occurs through a carefully crafted application that leverages improper handling of user-supplied data within the SPCom driver's kernel routines. When the vulnerable driver processes malicious input, it fails to properly validate buffer boundaries and memory access patterns, leading to potential memory corruption issues such as buffer overflows or use-after-free conditions. This flaw enables local attackers with regular application privileges to manipulate kernel memory structures and execute arbitrary code with kernel-level privileges, effectively bypassing Android's security model and gaining complete system control. The vulnerability is categorized under CWE-121 as a buffer overflow condition in kernel space, specifically manifesting as a heap-based buffer overflow that can be exploited through improper memory handling.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally undermines the security architecture of Android devices running vulnerable versions. Attackers can leverage this flaw to install persistent backdoors, modify system files, access sensitive user data, and potentially compromise the entire device. The vulnerability's exploitation requires local access and the ability to install a malicious application, making it particularly concerning in environments where users might be tricked into installing compromised applications. The attack surface is significant across Qualcomm-powered devices including smartphones, tablets, and other mobile platforms that utilize the affected driver component, affecting millions of devices in the wild.
Mitigation strategies for CVE-2016-5857 primarily focus on updating to Android 7.0 or later versions where Qualcomm has implemented proper input validation and memory management fixes within the SPCom driver. System administrators and device manufacturers should prioritize immediate patch deployment and implement robust application sandboxing measures to limit potential exploitation. Additionally, monitoring for suspicious kernel-level activities and implementing kernel exploit detection mechanisms can provide early warning capabilities. The vulnerability aligns with ATT&CK technique T1068 which describes local privilege escalation through kernel exploits, and represents a classic example of how driver-level vulnerabilities can be leveraged to achieve system compromise. Organizations should also consider implementing mobile device management solutions that can enforce security policies and prevent installation of untrusted applications that might exploit such kernel-level weaknesses.