CVE-2016-3807 in Android
Summary
by MITRE
The serial peripheral interface driver in Android before 2016-07-05 on Nexus 5X and 6P devices allows attackers to gain privileges via a crafted application, aka internal bug 28402196.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-3807 represents a critical privilege escalation flaw within the serial peripheral interface driver component of Android operating systems. This security weakness specifically affected Nexus 5X and 6P devices running Android versions prior to the 2016-07-05 security update. The vulnerability stems from insufficient input validation and access control mechanisms within the SPI driver implementation, creating a pathway for malicious applications to elevate their privileges and gain unauthorized system-level access. The flaw allows an attacker with a crafted application to exploit kernel-level components and potentially execute arbitrary code with elevated privileges, effectively bypassing the standard Android security model that separates user applications from system-level operations.
The technical exploitation of this vulnerability occurs through improper handling of SPI communication protocols within the kernel space. When a malicious application attempts to interact with the SPI driver, the system fails to properly validate the incoming data structures and access permissions, enabling attackers to manipulate memory locations and system registers that should only be accessible to trusted kernel components. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions, though the actual implementation involves more complex kernel privilege escalation mechanisms. The vulnerability demonstrates a classic example of insufficient privilege checks and improper input sanitization within kernel drivers, allowing userspace applications to influence kernel behavior through crafted inputs.
The operational impact of CVE-2016-3807 extends beyond simple privilege escalation, as it fundamentally compromises the security boundaries that protect Android devices from malicious applications. Once exploited, attackers can gain root access to the device, enabling them to modify system files, install persistent malware, access encrypted data, and potentially exfiltrate sensitive information. The vulnerability affects a significant portion of Android users who owned Nexus 5X and 6P devices during the affected timeframe, creating a substantial attack surface for threat actors. From an adversarial perspective, this vulnerability aligns with the MITRE ATT&CK framework's privilege escalation tactics, specifically targeting the T1068 technique for local privilege escalation, making it a valuable target for both nation-state actors and commercial threat groups seeking to compromise mobile devices.
Mitigation strategies for this vulnerability primarily focus on applying the Android security patches released on July 5, 2016, which addressed the underlying kernel driver implementation issues. Device manufacturers and security teams should prioritize immediate deployment of these updates across all affected Nexus devices and ensure proper testing of the patches to prevent system instability. Additionally, organizations should implement mobile device management policies that enforce automatic security updates and maintain comprehensive monitoring of device security status. The vulnerability serves as a reminder of the critical importance of kernel-level security in mobile operating systems and highlights the necessity for robust input validation and privilege separation mechanisms. Security professionals should also consider implementing network-based monitoring solutions to detect potential exploitation attempts and maintain detailed audit logs of system-level activities that could indicate successful privilege escalation attempts.