CVE-2016-8406 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-31796940.
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2016-8406 represents a significant information disclosure weakness within Android's kernel components that affects both kernel versions 3.10 and 3.18. This flaw exists across multiple critical subsystems including the ION memory management framework, Binder inter-process communication mechanism, USB driver stack, and networking components. The vulnerability operates at the kernel level, making it particularly dangerous as it can bypass traditional application-level security controls and access data that should be restricted to higher privilege processes. The issue is classified as moderate severity because it requires initial compromise of a privileged process to establish a foothold, but once achieved, it enables unauthorized data access beyond normal permission boundaries.
The technical root cause of this vulnerability stems from inadequate input validation and improper access control mechanisms within the kernel subsystems mentioned. The ION subsystem, which manages shared memory allocations, likely suffers from improper boundary checks that allow unauthorized memory access. Similarly, the Binder driver, which facilitates communication between processes, may have insufficient validation of incoming data structures that could lead to information leakage. The USB driver and networking components present additional attack surfaces where kernel memory corruption or improper access controls could expose sensitive data to malicious applications. This vulnerability aligns with CWE-200, which specifically addresses "Information Exposure," and demonstrates how kernel-level flaws can create persistent security weaknesses that undermine the entire system's security posture.
The operational impact of CVE-2016-8406 extends beyond simple data leakage as it creates a persistent backdoor for malicious applications to escalate privileges and access sensitive system information. Once a local attacker has compromised a privileged process, they can leverage this vulnerability to extract kernel memory contents, potentially including cryptographic keys, user credentials, or other sensitive data that should remain protected. The attack vector requires initial compromise of a privileged process, which means attackers must first gain access to a system with elevated privileges before exploiting this vulnerability. However, the consequences are severe as this creates a persistent information disclosure channel that can be used for further attacks or data exfiltration. The vulnerability affects Android's security model by undermining the principle of least privilege and creating potential pathways for privilege escalation attacks.
Mitigation strategies for CVE-2016-8406 should focus on both immediate patching and defensive measures within the Android ecosystem. The primary solution involves applying kernel updates that address the specific access control flaws in the ION subsystem, Binder driver, USB stack, and networking components. Organizations should implement robust process monitoring to detect unauthorized access attempts to privileged system components and establish network segmentation to limit potential lateral movement. The vulnerability demonstrates the importance of kernel-level security hardening and proper input validation across all subsystems. Security teams should also consider implementing runtime application protection mechanisms and enhanced logging to detect suspicious memory access patterns. This vulnerability highlights the critical need for comprehensive security testing of kernel components and proper adherence to security standards such as those outlined in the Android Security Model and the National Institute of Standards and Technology guidelines for kernel security. Regular security audits and vulnerability assessments should include thorough examination of kernel subsystems to identify similar access control weaknesses that could create similar information disclosure risks.