CVE-2016-3744 in Android
Summary
by MITRE
Buffer overflow in the create_pbuf function in btif/src/btif_hh.c in Bluetooth in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-07-01 allows remote attackers to gain privileges via a crafted pairing operation, aka internal bug 27930580.
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Analysis
by VulDB Data Team • 02/21/2019
The vulnerability identified as CVE-2016-3744 represents a critical buffer overflow flaw within the Bluetooth implementation of Android operating systems. This security weakness exists in the create_pbuf function located in the btif/src/btif_hh.c file, which is part of the Bluetooth HID (Human Interface Device) subsystem. The vulnerability specifically affects Android versions 4.x prior to 4.4.4, 5.0.x prior to 5.0.2, 5.1.x prior to 5.1.1, and 6.x releases before the 2016-07-01 security update timeline. The flaw allows remote attackers to execute privilege escalation attacks through carefully crafted pairing operations, making it particularly dangerous in mobile environments where Bluetooth connectivity is frequently utilized.
The technical nature of this buffer overflow stems from inadequate input validation within the create_pbuf function which handles Bluetooth HID report data. When a malicious device attempts to pair with an affected Android device, the system processes HID report descriptors without proper bounds checking on the data length. This allows an attacker to send oversized data packets that exceed the allocated buffer space, causing memory corruption that can be exploited to execute arbitrary code with elevated privileges. The vulnerability operates at the Bluetooth protocol level and specifically targets the HID profile implementation, making it distinct from typical network-based buffer overflows. According to CWE classification, this represents a CWE-121: Stack-based Buffer Overflow, where the buffer overflow occurs in a stack-based data structure during Bluetooth HID report processing.
The operational impact of this vulnerability is severe as it enables remote code execution with system-level privileges, effectively allowing attackers to gain complete control over affected Android devices. An attacker positioned within Bluetooth range can exploit this vulnerability during the pairing process without requiring any user interaction or physical access to the device. Once successfully exploited, the malicious actor could install malware, access sensitive data, modify system configurations, or even create persistent backdoors. The attack vector is particularly concerning because Bluetooth pairing is a common and routine operation on mobile devices, making the exploitation opportunities frequent and potentially widespread. This vulnerability directly aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: Python and T1068 for Exploitation for Privilege Escalation, as it enables both remote code execution and privilege elevation through a well-defined attack pathway.
Mitigation strategies for CVE-2016-3744 primarily focus on applying the appropriate security patches released by Google and device manufacturers. Organizations should immediately update all affected Android devices to the latest available versions, particularly ensuring that Android 4.4.4, 5.0.2, 5.1.1, and the corresponding 2016-07-01 security updates are deployed. Network administrators should implement Bluetooth access controls and disable unnecessary Bluetooth services when not actively required. Device manufacturers should consider implementing additional runtime protections such as stack canaries and address space layout randomization to make exploitation more difficult. Regular security assessments should include Bluetooth protocol analysis to identify potential vulnerabilities in wireless communication stacks. The vulnerability also highlights the importance of proper input validation in embedded systems and wireless protocols, demonstrating how seemingly benign Bluetooth HID operations can become attack vectors when proper bounds checking is absent. This flaw underscores the necessity for comprehensive security testing of wireless communication protocols and the critical need for timely patch management in mobile operating systems.