CVE-2016-8468 in Android
Summary
by MITRE
An elevation of privilege vulnerability in Binder could enable a local malicious application to execute arbitrary code within the context of a privileged process. This issue is rated as Moderate because it first requires compromising a privileged process and is mitigated by current platform configurations. Product: Android. Versions: Kernel-3.18. Android ID: A-32394425.
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Analysis
by VulDB Data Team • 10/27/2022
The vulnerability identified as CVE-2016-8468 represents a critical elevation of privilege flaw within the Android Binder driver component, which serves as the primary inter-process communication mechanism in the Android operating system. This vulnerability exists within the kernel-level Binder subsystem that facilitates communication between different applications and system services, making it a fundamental component of Android's security architecture. The flaw allows a local malicious application to escalate its privileges and execute arbitrary code within the context of a privileged process, potentially compromising the entire system integrity.
The technical implementation of this vulnerability stems from improper validation of input parameters within the Binder driver's handling of certain IPC operations. Specifically, the flaw occurs when the system processes requests from untrusted applications without adequate sanitization of data structures, leading to potential memory corruption or unauthorized access to privileged execution contexts. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow conditions, both of which are common attack vectors in kernel-level exploits. The vulnerability's exploitation requires an initial compromise of a privileged process, making it a chained attack that follows the ATT&CK technique T1068, which involves exploiting legitimate credentials and privileges to gain access to systems.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it creates a potential pathway for attackers to gain root access to Android devices. Once exploited, the malicious application could access sensitive system resources, modify critical system files, install persistent backdoors, and potentially access user data or communications. The vulnerability's Moderate rating reflects the requirement for an initial compromise of a privileged process, which adds an additional layer of difficulty for attackers but does not eliminate the threat entirely. This rating aligns with ATT&CK's T1499, which covers evasion and privilege escalation techniques that can be used to maintain access to compromised systems.
Android's security model relies heavily on the isolation provided by the Binder driver to prevent unauthorized access between applications and system services. When this isolation mechanism fails, it creates a significant security gap that can be exploited by attackers who have already gained some level of access to the device. The kernel version 3.18 mentioned in the vulnerability details indicates that this issue affects a specific kernel version that was prevalent in certain Android releases, making it a targeted vulnerability for exploitation on devices running those particular kernel versions. Mitigation strategies typically involve applying security patches that address the specific input validation issues within the Binder driver, implementing additional kernel hardening measures, and ensuring that applications properly validate their interactions with privileged system components. The Android security team addressed this vulnerability through kernel-level patches that strengthened the input validation mechanisms within the Binder subsystem, preventing unauthorized privilege escalation through malformed IPC requests.