CVE-2016-8421 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the Qualcomm Wi-Fi driver could enable a local malicious application to execute arbitrary code within the context of the kernel. This issue is rated as High because it first requires compromising a privileged process. Product: Android. Versions: Kernel-3.10, Kernel-3.18. Android ID: A-32451104. References: QC-CR#1087797.
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Analysis
by VulDB Data Team • 11/12/2022
The vulnerability described in CVE-2016-8421 represents a critical elevation of privilege flaw within the Qualcomm Wi-Fi driver component of Android operating systems. This issue resides in the kernel-level driver code that manages wireless network connectivity, specifically affecting Android devices running kernel versions 3.10 and 3.18. The vulnerability allows a local malicious application to escalate its privileges and execute arbitrary code with kernel-level permissions, effectively bypassing the normal security boundaries that separate user-space applications from the core operating system. The classification as High severity stems from the requirement to first compromise a privileged process, which creates a more complex attack vector but still represents a significant security weakness in the Android platform's defense-in-depth strategy.
The technical flaw manifests through improper input validation and memory management within the Qualcomm Wi-Fi driver implementation. When a malicious application attempts to interact with the driver through specific ioctl calls or other kernel interfaces, the driver fails to properly validate the parameters or handle memory operations, creating potential for buffer overflows, use-after-free conditions, or other memory corruption vulnerabilities. This memory corruption can be exploited to manipulate kernel data structures, overwrite function pointers, or redirect execution flow to malicious code injected by the compromised application. The vulnerability directly maps to CWE-119 Improper Restriction of Operations within a Memory Buffer and CWE-787 Out-of-bounds Write, both of which are common attack vectors in kernel-level exploits. The attack surface is particularly concerning because Wi-Fi drivers are frequently accessed by various system components and user applications, increasing the likelihood of successful exploitation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over the device's kernel execution environment. Once successfully exploited, the malicious application can modify system files, disable security features, install persistent backdoors, and access all device data without user consent. The exploitability requires initial compromise of a privileged process, which aligns with ATT&CK technique T1068 Exploitation for Privilege Escalation, but once achieved, the attacker gains the ability to perform actions equivalent to root access. This vulnerability affects a wide range of Android devices that utilize Qualcomm chipsets, particularly those running versions of Android that incorporate the affected kernel versions, creating a substantial attack surface across multiple device manufacturers and model lines.
Mitigation strategies for CVE-2016-8421 should focus on both immediate patching and defensive measures. Device manufacturers and security teams must prioritize applying the relevant kernel patches provided by Qualcomm and Android security teams, which typically address the specific memory corruption vulnerabilities in the Wi-Fi driver code. Organizations should implement robust application sandboxing policies to minimize the risk of privilege escalation through compromised applications, while also monitoring for unusual network activity that might indicate exploitation attempts. The security community should consider implementing behavioral monitoring for kernel-level operations that could indicate exploitation attempts, particularly around Wi-Fi driver interfaces. Additionally, users should be advised to avoid installing untrusted applications and to maintain regular security updates, as this vulnerability represents a classic example of how driver-level flaws can create persistent security risks that require coordinated patch management across multiple software layers. The vulnerability also underscores the importance of secure coding practices in kernel drivers and the need for comprehensive security testing of low-level system components before deployment.