CVE-2016-3857 in Android
Summary
by MITRE
The kernel in Android before 2016-08-05 on Nexus 7 (2013) devices allows attackers to gain privileges via a crafted application, aka internal bug 28522518.
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Analysis
by VulDB Data Team • 10/06/2024
This vulnerability represents a critical privilege escalation flaw in the Android kernel affecting Nexus 7 (2013) devices released before the security patch date of August 5, 2016. The issue stems from improper kernel-level access controls that allow malicious applications to elevate their privileges from standard user-level permissions to full system-level access. This type of vulnerability falls under the CWE-264 category of "Permissions, Privileges, and Access Controls" and represents a fundamental breakdown in the Android security model's ability to enforce proper privilege boundaries between applications and the underlying operating system.
The technical implementation of this vulnerability exploits a flaw in the kernel's handling of system calls or memory management routines that govern how applications interact with kernel space. Attackers can craft malicious applications that leverage this kernel flaw to bypass normal security restrictions and gain root access to the device. This privilege escalation occurs without requiring any user interaction or physical access to the device, making it particularly dangerous as it can be exploited remotely through malicious app downloads or installations. The vulnerability specifically targets the kernel's security mechanisms that should prevent user-space applications from directly manipulating kernel data structures or executing privileged operations.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it fundamentally compromises the security posture of affected devices. Once an attacker gains root access through this exploit, they can bypass all Android security controls including application sandboxing, encryption protections, and user authentication mechanisms. This enables complete device compromise with access to all stored data, communication channels, and system functionalities. The vulnerability affects devices that were already vulnerable to various other exploits due to their age and the lack of security updates, making them particularly attractive targets for threat actors. This type of attack vector aligns with ATT&CK technique T1068 which involves local privilege escalation through kernel exploits, and T1566 which covers social engineering and malicious application delivery.
Mitigation strategies for this vulnerability require immediate deployment of the security patch released by Google on August 5, 2016, which addressed the specific kernel flaw in the Nexus 7 (2013) device line. Organizations and individuals should ensure their devices are updated to the latest available Android security patch level, as older devices may no longer receive security updates from manufacturers. System administrators should implement strict application control policies to prevent installation of untrusted applications, while also monitoring for any suspicious behavior that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of timely security patch management and the risks associated with using end-of-life devices that no longer receive security updates. Additionally, security professionals should consider implementing device monitoring solutions that can detect unusual privilege escalation patterns or kernel-level anomalies that might indicate exploitation of similar vulnerabilities.