CVE-2016-6683 in Android
Summary
by MITRE
The kernel in Android before 2016-10-05 on Nexus devices allows attackers to obtain sensitive information via a crafted application, aka internal bug 30143283.
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Analysis
by VulDB Data Team • 05/01/2019
The vulnerability identified as CVE-2016-6683 represents a critical information disclosure flaw within the Android kernel ecosystem that affected Nexus devices prior to the 2016-10-05 security update. This vulnerability stems from insufficient input validation and improper access control mechanisms within the kernel's memory management subsystem, specifically impacting how the system handles memory allocation and access permissions for user-space applications. The flaw enables malicious actors to craft specially designed applications that can exploit kernel-level memory structures to extract sensitive information from the device's memory space, potentially exposing system internals, user credentials, or confidential data that should remain protected within kernel memory boundaries.
The technical implementation of this vulnerability involves a race condition or improper privilege escalation mechanism within the kernel's memory management unit that allows unprivileged user applications to access kernel memory regions that should be restricted. This typically occurs through manipulation of system calls or memory mapping operations that do not properly validate the requesting process's privileges or the legitimacy of memory access patterns. The vulnerability operates at the kernel level, making it particularly dangerous as it bypasses standard user-space security controls and can be exploited without requiring physical access to the device or elevated privileges. Attackers can leverage this flaw to perform memory reads from kernel memory locations that contain sensitive data such as encryption keys, user credentials, or system configuration information.
The operational impact of CVE-2016-6683 extends beyond simple information disclosure, as the extracted kernel memory data can provide attackers with significant insights into the device's internal architecture and security mechanisms. This information can be used to develop more sophisticated attacks targeting other vulnerabilities within the same system or to bypass additional security controls. The vulnerability affects all Nexus devices running Android versions prior to the specified patch date, making it particularly widespread across the Android ecosystem since Nexus devices were often used as reference platforms for Android development and security research. The attack vector requires only the installation of a malicious application, which can be delivered through various means including third-party app stores, social engineering campaigns, or compromised applications that users might legitimately install.
Mitigation strategies for CVE-2016-6683 primarily focus on applying the security patch released by Google on 2016-10-05, which addresses the underlying kernel memory management flaw through enhanced input validation and stricter access control mechanisms. Organizations and users should prioritize immediate patch deployment across all affected Nexus devices, as the vulnerability remains exploitable in unpatched systems. Additional defensive measures include implementing application whitelisting policies to prevent installation of untrusted applications, monitoring for suspicious memory access patterns, and conducting regular security audits of device configurations. From a cybersecurity perspective, this vulnerability aligns with CWE-200, which addresses improper information exposure, and represents a classic example of how kernel-level flaws can provide attackers with extensive access to system internals. The vulnerability also maps to ATT&CK technique T1059, specifically focusing on command and scripting interpreter usage for privilege escalation, and T1068, which covers privilege escalation through kernel exploits. Device manufacturers should consider implementing additional memory protection mechanisms such as kernel address space layout randomization and enhanced memory access controls to prevent similar vulnerabilities from emerging in future kernel implementations.