CVE-2016-6781 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the MediaTek driver could enable a local malicious application to execute arbitrary code within the context of the kernel. This issue is rated as High because it first requires compromising a privileged process. Product: Android. Versions: Kernel-3.10. Android ID: A-31095175. References: MT-ALPS02943455.
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2016-6781 represents a critical elevation of privilege flaw within MediaTek driver components that operate at the kernel level on Android devices. This weakness allows a local malicious application to escalate its privileges and execute arbitrary code with kernel-level permissions, effectively bypassing the security boundaries that normally protect the operating system from unauthorized access. The vulnerability resides in the MediaTek driver implementation, which serves as a crucial interface between hardware components and the Android kernel, making it a prime target for exploitation by attackers who can manipulate the system through legitimate application interfaces.
The technical nature of this flaw stems from improper input validation and privilege management within the MediaTek driver code, specifically within the kernel module that handles hardware abstraction layer communications. When a malicious application attempts to interact with the compromised driver, it can manipulate kernel memory structures or function pointers to gain unauthorized access to kernel execution contexts. This type of vulnerability typically involves buffer overflows, use-after-free conditions, or improper access control mechanisms that allow user-space processes to manipulate kernel data structures directly. The vulnerability's classification as High severity reflects the requirement for an attacker to first compromise a privileged process, which provides a foothold for further exploitation and escalation.
The operational impact of CVE-2016-6781 extends far beyond simple privilege escalation, as successful exploitation can result in complete system compromise and persistent backdoor access. Once an attacker achieves kernel-level execution, they can modify system files, disable security mechanisms, install rootkits, and maintain long-term access to the device. The vulnerability affects Android devices running kernel version 3.10, which represents a significant portion of the Android ecosystem during that time period, making it particularly dangerous for widespread exploitation. This type of vulnerability directly impacts the Android security model by undermining the fundamental principle that user applications should be isolated from kernel-level operations and system resources.
Mitigation strategies for this vulnerability primarily involve patching the MediaTek driver components with updated firmware and kernel modules that address the privilege escalation mechanisms. System administrators and device manufacturers should prioritize applying security updates from their respective vendors to remediate the vulnerability. Additionally, implementing runtime protections such as kernel address space layout randomization kASLR, stack canaries, and code integrity checks can help prevent exploitation attempts. From a cybersecurity perspective, this vulnerability aligns with CWE-264, which describes permissions, privileges, and access control issues, and may be mapped to ATT&CK technique T1068, which covers exploit for privilege escalation. The vulnerability demonstrates the critical importance of secure driver development practices and the need for comprehensive security testing of hardware abstraction layers in mobile operating systems. Organizations should also consider implementing mobile device management solutions that can detect and prevent exploitation attempts, as well as maintaining robust incident response procedures to address potential compromises.