CVE-2016-8402 in Android
Summary
by MITRE
An information disclosure vulnerability in kernel components including the ION subsystem, Binder, USB driver and networking subsystem could enable a local malicious application to access data outside of its permission levels. This issue is rated as Moderate because it first requires compromising a privileged process. Product: Android. Versions: Kernel-3.10, Kernel-3.18. Android ID: A-31495231.
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2016-8402 represents a significant information disclosure flaw within Android's kernel components that affects both kernel versions 3.10 and 3.18. This weakness resides in multiple critical subsystems including the ION memory management framework, Binder inter-process communication mechanism, USB driver implementations, and networking components. The vulnerability operates at the kernel level, making it particularly dangerous as it can be exploited to bypass standard Android security boundaries and access data that should normally be restricted to authorized processes. The issue is classified as moderate severity because it requires initial compromise of a privileged process to achieve exploitation, but once achieved, it provides extensive access to system resources and sensitive information.
The technical flaw stems from inadequate input validation and insufficient access controls within the kernel subsystems mentioned. The ION subsystem, which manages memory allocation for graphics and multimedia operations, likely contains improper bounds checking that allows malicious applications to read beyond allocated memory regions. Similarly, the Binder driver, which facilitates communication between applications and system services, may lack proper validation of incoming data structures that could be manipulated to extract information from other processes. The USB driver and networking subsystems probably exhibit similar vulnerabilities where kernel memory can be accessed through malformed input or improper privilege checks. This type of vulnerability aligns with CWE-200, which specifically addresses "Information Exposure" and represents a classic case of insufficient access control mechanisms allowing unauthorized data access.
From an operational impact perspective, this vulnerability enables a local malicious application to escalate its privileges and access data that normally would be restricted to higher-privilege processes or system components. An attacker who has already compromised a privileged process can leverage this vulnerability to extract sensitive information from other running processes, potentially including cryptographic keys, user credentials, application data, and system configuration information. The attack vector requires local execution and already compromised privileges, but the impact is significant as it allows for lateral movement within the system and access to data that should remain protected. This vulnerability particularly affects Android devices where applications may have been granted elevated permissions through various attack vectors, making the exploitation chain more feasible in real-world scenarios.
The exploitation of this vulnerability demonstrates characteristics consistent with ATT&CK technique T1056.001, which involves input injection attacks that can be used to manipulate kernel components and gain unauthorized access to system resources. The attack requires an initial foothold through privilege escalation or other means to compromise a privileged process, after which the information disclosure can be achieved through kernel memory manipulation. Mitigation strategies should focus on implementing comprehensive kernel hardening measures including strict input validation, enhanced access controls, and regular security updates to patch the identified vulnerabilities. System administrators should ensure that privileged processes are properly secured and that unnecessary permissions are not granted to applications. Additionally, monitoring for unusual memory access patterns and implementing proper privilege separation mechanisms can help detect and prevent exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date kernel versions and following security best practices for Android device management and application sandboxing.