CVE-2016-3771 in Android
Summary
by MITRE
The MediaTek drivers in Android before 2016-07-05 on Android One devices allow attackers to gain privileges via a crafted application, aka Android internal bug 29007611 and MediaTek internal bug ALPS02703102.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-3771 represents a critical privilege escalation flaw affecting MediaTek-based Android devices, particularly those running Android versions prior to July 5, 2016. This issue specifically targets the MediaTek driver implementations within the Android operating system, creating a pathway for malicious applications to elevate their privileges from standard user-level access to system-level control. The vulnerability stems from improper input validation and privilege handling within the MediaTek hardware abstraction layer components that manage device-specific functionalities. Attackers can exploit this weakness by crafting a specially designed application that leverages the flawed driver interfaces to execute arbitrary code with elevated privileges, effectively bypassing the normal Android security model that separates user applications from system-level operations.
The technical exploitation of this vulnerability occurs through the manipulation of MediaTek driver interfaces that are typically accessed by system processes but are improperly protected against malicious application access. This flaw falls under the category of privilege escalation vulnerabilities, specifically categorized as CWE-264, which deals with Permissions, Privileges, and Access Controls. The vulnerability allows an attacker to gain root-level access to the device, enabling them to modify system files, install malicious software, access sensitive data, and potentially compromise the entire device. The attack vector is particularly concerning because it requires no special user interaction beyond installing the malicious application, making it a serious threat to Android One devices and other MediaTek-powered smartphones that were vulnerable to this specific flaw. The underlying issue is that the MediaTek drivers do not properly validate the privileges of applications attempting to access their interfaces, allowing unauthorized code execution with system-level permissions.
The operational impact of CVE-2016-3771 extends beyond individual device compromise, as it affects a significant portion of Android One devices and other MediaTek-based smartphones released prior to the patch release. This vulnerability creates a persistent threat vector that can be exploited by attackers to establish persistent backdoors on affected devices, potentially enabling large-scale surveillance operations or data theft campaigns. The exploitation of this flaw can lead to complete device compromise, allowing attackers to access all user data including messages, photos, contacts, and sensitive personal information. Additionally, the vulnerability can be leveraged to install additional malware, modify system configurations, and potentially create a botnet of compromised devices. The attack surface is particularly broad as it affects not just individual users but also organizations that deploy these devices, creating potential corporate security risks. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques under T1068, where attackers can leverage system-level access to perform further malicious activities.
Mitigation strategies for CVE-2016-3771 primarily involve applying the security patches released by Google and MediaTek, which address the privilege escalation flaw in the driver interfaces. Device users should ensure their Android One devices are updated to the latest available security patches, particularly those released after July 5, 2016. System administrators should implement device management policies that enforce automatic security updates and regularly audit device security configurations. Network administrators should monitor for suspicious activities that might indicate exploitation attempts, particularly on devices that have not been updated. Organizations should also consider implementing mobile device management solutions that can help enforce security policies and automatically patch vulnerable devices. The vulnerability highlights the importance of proper driver security implementation and the need for comprehensive security testing of hardware abstraction layers. Security professionals should also consider the broader implications of hardware-specific vulnerabilities and implement layered security approaches that can protect against similar flaws in other device components. The remediation process requires careful consideration of device compatibility and the potential for patch-related issues that could affect device functionality, particularly for older devices that may not support newer security updates.