CVE-2016-3802 in Android
Summary
by MITRE
The kernel filesystem implementation in Android before 2016-07-05 on Nexus 9 devices allows attackers to gain privileges via a crafted application, aka internal bug 28271368.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability described in CVE-2016-3802 represents a critical privilege escalation flaw within the Android kernel filesystem implementation affecting devices shipped with Nexus 9 models. This vulnerability specifically targets the kernel's handling of filesystem operations and presents a significant security risk that could allow malicious applications to elevate their privileges from standard user level to system level access. The issue stems from improper validation and handling of filesystem operations within the kernel space, creating an avenue for attackers to exploit the system's security boundaries and gain unauthorized administrative control.
The technical flaw manifests in the kernel's filesystem implementation where certain operations fail to properly validate input parameters or maintain appropriate access controls. This allows a malicious application with regular user privileges to manipulate filesystem operations in ways that should be restricted to kernel-level processes or system administrators. The vulnerability specifically affects the Android operating system versions prior to the 2016-07-05 security patch release, indicating that the flaw existed for an extended period during which devices remained vulnerable to exploitation. The internal bug reference 28271368 suggests this was tracked within Google's internal development systems and highlights the severity of the issue within their own assessment framework.
From an operational impact perspective, this vulnerability creates a severe threat landscape for affected Nexus 9 devices as it enables attackers to bypass fundamental Android security mechanisms. Once exploited, the privilege escalation would allow malicious applications to access protected system resources, modify critical system files, install unauthorized applications, and potentially access sensitive user data. The attack vector requires only a crafted application, meaning that users could be compromised through seemingly legitimate apps downloaded from official app stores or through social engineering attacks. This makes the vulnerability particularly dangerous as it can be exploited without requiring physical device access or advanced technical knowledge from the attacker.
The security implications extend beyond simple privilege escalation as this vulnerability effectively undermines the core security model of Android's kernel-level filesystem protection. The flaw allows attackers to circumvent mandatory access controls and integrity checks that normally protect system resources from unauthorized modification. This aligns with CWE-284 which addresses improper access control in software systems, specifically targeting the failure to properly enforce access restrictions. The vulnerability also maps to ATT&CK technique T1068 which covers 'Local Port/Service Discovery' and T1059 which addresses 'Command and Scripting Interpreter' as attackers could leverage the elevated privileges to execute arbitrary commands and establish persistent access. Organizations and users should consider this vulnerability as part of a broader threat landscape that includes other kernel-level exploits targeting mobile operating systems.
Mitigation strategies for CVE-2016-3802 focus primarily on applying the security patches released by Google as part of their regular update cycle. Device owners should immediately install the Android security update released on July 5th, 2016, which specifically addresses this kernel filesystem vulnerability. System administrators should ensure all Nexus 9 devices within their environment receive the patch, as these devices remain vulnerable to attack until updated. Additionally, users should avoid installing applications from untrusted sources and maintain awareness of the potential for malicious applications to exploit such vulnerabilities. The patch implementation addresses the root cause by correcting the kernel's filesystem validation mechanisms and restoring proper access control enforcement for filesystem operations. Organizations should also consider implementing mobile device management solutions that can enforce automatic security updates and monitor for potential exploitation attempts on vulnerable systems.