CVE-2016-3842 in Android
Summary
by MITRE
The Qualcomm GPU driver in Android before 2016-08-05 on Nexus 5X, 6, and 6P devices allows attackers to gain privileges via a crafted application, aka Android internal bug 28377352 and Qualcomm internal bug CR1002974.
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Analysis
by VulDB Data Team • 03/20/2019
The vulnerability identified as CVE-2016-3842 represents a critical privilege escalation flaw within the Qualcomm GPU driver component of Android operating systems. This security weakness specifically affected Nexus 5X, 6, and 6P devices released prior to the August 5, 2016 security update cycle. The flaw stems from improper input validation and access control mechanisms within the GPU driver's kernel space implementation, creating a pathway for malicious applications to elevate their privileges from standard user-level access to system-level administrative rights. The vulnerability was tracked internally by both Android and Qualcomm as bug numbers 28377352 and CR1002974 respectively, indicating its significance within their respective development tracking systems. This issue falls under the CWE-264 category of permissions, privileges, and access control, specifically manifesting as an improper access control vulnerability that allows unauthorized privilege escalation.
The technical exploitation of this vulnerability occurs through a crafted application that leverages memory corruption or privilege escalation techniques within the GPU driver's kernel module. Attackers can manipulate the GPU driver's handling of graphics commands or memory management operations to execute arbitrary code with elevated privileges. The GPU driver in question processes graphics rendering commands from applications and manages hardware resources, making it a prime target for attackers seeking to gain system-level access. When an application submits malformed graphics commands or exploits memory handling flaws in the driver, it can trigger a condition that allows privilege elevation. This typically involves manipulating kernel memory structures or exploiting race conditions in the driver's command processing pipeline, enabling the malicious application to bypass Android's standard security model and gain root access to the device. The vulnerability's impact extends beyond simple application compromise since it provides attackers with complete system control, including access to all user data, device functions, and the ability to install malicious software.
The operational impact of this vulnerability is severe and far-reaching across multiple threat vectors. Devices running affected Android versions become susceptible to sophisticated attacks that can result in complete device compromise, data theft, and persistent backdoor installation. The vulnerability affects millions of devices since Nexus 5X, 6, and 6P were popular flagship devices with significant market presence. Attackers can leverage this flaw to install malware, monitor user activities, steal sensitive information, or create persistent access points for further exploitation. The privilege escalation capability means that even applications that normally cannot access system resources can gain full administrative control, effectively neutralizing Android's security boundaries. This vulnerability also impacts enterprise environments where these devices may be used for business purposes, potentially exposing corporate data and network access. The exploitation of this flaw demonstrates the critical importance of timely security updates, as users who did not install the August 2016 patches remained vulnerable to attacks. This vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation, and T1547, covering registry run keys and startup folder, as attackers could establish persistence through elevated privileges gained via this vulnerability.
Mitigation strategies for CVE-2016-3842 primarily focus on applying the security patches released by Google and Qualcomm in their August 2016 updates. Users must ensure their devices receive and install the latest security patches, particularly the Android security bulletins from August 2016 that addressed this specific vulnerability. Device manufacturers and carriers should prioritize timely delivery of security updates to affected users. In environments where immediate patching is not possible, administrators should implement network monitoring to detect suspicious GPU driver activity and application behavior. The vulnerability also highlights the need for comprehensive security testing of driver components, particularly those handling graphics processing and hardware acceleration. Organizations should consider device segmentation and network access controls to limit the impact if devices become compromised. Additionally, security researchers and penetration testers should include GPU driver security assessments in their testing protocols, as this vulnerability demonstrates how hardware driver components can serve as attack vectors for privilege escalation. The incident underscores the importance of maintaining up-to-date device firmware and the necessity of implementing robust patch management processes to prevent exploitation of known vulnerabilities.