CVE-2016-8401 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-31494725.
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2016-8401 represents a significant information disclosure flaw within Android's kernel components that affects both kernel versions 3.10 and 3.18. This vulnerability operates at the system level and specifically targets multiple kernel subsystems including the ION memory management system, Binder inter-process communication mechanism, USB driver framework, and networking components. The flaw allows a local malicious application to bypass normal permission boundaries and access data that should be restricted to higher privilege levels. According to the Android security team's assessment, this vulnerability requires initial compromise of a privileged process before exploitation can occur, which places it in the moderate severity category. The vulnerability stems from inadequate access controls and memory management protections within the kernel subsystems, creating potential pathways for unauthorized data access. The ION subsystem, which manages shared memory allocations, the Binder driver responsible for process communication, USB drivers handling device interactions, and networking components all contribute to this vulnerability through insufficient validation of access permissions and memory boundaries.
The technical implementation of this vulnerability exploits weaknesses in kernel-level memory management and access control mechanisms that should normally prevent unprivileged applications from accessing sensitive kernel data structures. Attackers can leverage this flaw to read kernel memory contents, potentially accessing sensitive information such as cryptographic keys, user credentials, or other confidential data stored in kernel memory regions. The vulnerability manifests when a compromised privileged process attempts to manipulate kernel memory through the affected subsystems, creating opportunities for information leakage that extends beyond normal application boundaries. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and aligns with ATT&CK technique T1003 for OS Credential Dumping, where attackers can extract sensitive information from kernel memory. The exploitation chain typically involves initial compromise of a privileged process followed by manipulation of kernel subsystems to read unauthorized memory regions, potentially leading to complete system compromise.
The operational impact of CVE-2016-8401 extends beyond simple information disclosure as it creates potential pathways for more sophisticated attacks. Once an attacker gains access to kernel memory through this vulnerability, they could potentially extract cryptographic keys used for encryption, access user session tokens, or obtain other sensitive credentials that would allow further system compromise. The vulnerability affects the core Android operating system kernel, meaning that successful exploitation could undermine the entire security model of the device. This type of vulnerability is particularly concerning because it operates below the application layer, making detection and prevention more challenging. The attack surface includes not only the affected kernel subsystems but also the potential for escalation to full system compromise. The vulnerability's presence in both kernel 3.10 and 3.18 versions indicates it was a widespread issue affecting multiple Android versions, creating significant risk across the Android ecosystem. Organizations should implement immediate patching strategies and monitor for potential exploitation attempts, while also considering the broader implications for device security and the need for enhanced kernel memory protection mechanisms.
Mitigation strategies for CVE-2016-8401 should focus on both immediate patching and long-term security hardening measures. The primary solution involves applying the relevant kernel patches that address the specific memory access control issues in the affected subsystems, particularly within the ION memory manager, Binder driver, USB components, and networking stack. Security teams should also implement enhanced monitoring for suspicious memory access patterns and kernel-level activities that might indicate exploitation attempts. The vulnerability's classification as moderate severity means that organizations should prioritize patching in environments where privileged processes might be compromised, as this represents a critical escalation path. Additionally, implementing kernel memory protection features such as kernel address space layout randomization and enhanced memory access controls can help reduce the impact of similar vulnerabilities. Organizations should also consider implementing application sandboxing and privilege separation mechanisms to limit the potential damage from compromised privileged processes. Regular security audits of kernel subsystems and memory management components are essential to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.