CVE-2016-3801 in Android
Summary
by MITRE
The MediaTek GPS driver in Android before 2016-07-05 on Android One devices allows attackers to gain privileges via a crafted application, aka Android internal bug 28174914 and MediaTek internal bug ALPS02688853.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-3801 represents a critical privilege escalation flaw within the MediaTek GPS driver component of Android operating systems. This issue specifically affected Android One devices and persisted in versions prior to the 2016-07-05 security update. The vulnerability stems from improper input validation and access control mechanisms within the GPS driver kernel module, creating a pathway for malicious applications to elevate their privileges from standard user-level access to system-level privileges. The flaw was particularly concerning as it allowed attackers to exploit a legitimate system component to gain unauthorized administrative control over affected devices.
The technical implementation of this vulnerability involves a specific flaw in how the MediaTek GPS driver handles certain ioctl (input/output control) commands and memory operations. When a crafted application invokes specific driver interfaces with malformed parameters, the driver fails to properly validate the input data, leading to a buffer overflow condition or arbitrary code execution within kernel space. This kernel-level execution context provides attackers with the ability to bypass standard Android security mechanisms including SELinux policies and user permission controls. The vulnerability specifically manifests through improper bounds checking and lack of proper access validation when processing GPS-related data streams, making it particularly dangerous as it operates at the core system level where normal security boundaries do not apply.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise capabilities. Once an attacker achieves system-level privileges through this vulnerability, they can manipulate any system resources including accessing encrypted data, modifying system files, installing malicious applications, and potentially disabling security features. The vulnerability affects Android One devices specifically, which were designed as budget-friendly smartphones with simplified software configurations, making them particularly susceptible to such attacks. The timeframe of the vulnerability's existence, spanning from the initial Android release through the 2016-07-05 patch, indicates a prolonged window during which affected devices remained vulnerable to exploitation, creating significant risk for users who did not receive timely security updates.
Security researchers have classified this vulnerability under CWE-119 Improper Access Control and CWE-787 Out-of-bounds Write, reflecting both the access control failure and memory corruption aspects of the flaw. The vulnerability's presence in the MediaTek GPS driver aligns with ATT&CK technique T1068 Exploitation for Privilege Escalation, where attackers leverage system vulnerabilities to gain elevated privileges. The attack vector specifically involves a malicious application that can be distributed through legitimate app stores or via social engineering tactics, making the vulnerability particularly insidious as it requires no physical access or specialized equipment to exploit. The vulnerability demonstrates the inherent risks of complex kernel-level drivers and highlights the importance of proper input validation and access control mechanisms in system components that interface with hardware peripherals. Mitigation efforts required immediate security patches from device manufacturers and Google, with users needing to install the Android security update released on July 5, 2016, to resolve the vulnerability and restore proper privilege separation within the operating system.