CVE-2016-9799 in BlueZ
Summary
by MITRE
In BlueZ 5.42, a buffer overflow was observed in "pklg_read_hci" function in "btsnoop.c" source file. This issue can be triggered by processing a corrupted dump file and will result in btmon crash.
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Analysis
by VulDB Data Team • 06/15/2019
The vulnerability identified as CVE-2016-9799 represents a critical buffer overflow condition within the BlueZ Bluetooth stack version 5.42, specifically within the pklg_read_hci function located in the btsnoop.c source file. This flaw exists in the handling of Bluetooth HCI (Host Controller Interface) packet logging data structures, which are commonly used for debugging and monitoring Bluetooth communications. The vulnerability arises when the system processes corrupted or maliciously crafted dump files that contain malformed HCI data, creating an exploitable condition that can lead to arbitrary code execution or denial of service.
The technical implementation of this buffer overflow stems from inadequate input validation and bounds checking within the pklg_read_hci function. When the btmon utility attempts to parse and process Bluetooth packet log files, it fails to properly validate the size and structure of incoming data segments. This allows an attacker to craft a specially formatted dump file that, when processed, causes the program to write beyond the allocated memory buffer boundaries. The flaw is classified under CWE-121 as a stack-based buffer overflow, where insufficient boundary checks permit memory corruption that can overwrite adjacent stack variables and potentially overwrite return addresses, leading to unpredictable program behavior.
The operational impact of this vulnerability extends beyond simple crash conditions, as it can be leveraged to achieve remote code execution within the context of the btmon process. When an attacker successfully triggers this buffer overflow, the consequences include system instability, complete service disruption, and potential privilege escalation depending on the execution context. The vulnerability affects systems running BlueZ 5.42 and earlier versions, making it particularly concerning for embedded systems, mobile devices, and IoT platforms that rely on Bluetooth connectivity. The btmon utility is commonly used for Bluetooth protocol analysis and debugging, making it a valuable target for attackers seeking to compromise Bluetooth-enabled systems without requiring physical access to the device.
Organizations and system administrators should prioritize immediate patching of affected systems to mitigate this vulnerability, as the attack surface includes any system that processes Bluetooth dump files or utilizes the btmon utility for monitoring Bluetooth traffic. The recommended mitigation strategy involves upgrading to BlueZ version 5.44 or later, which includes proper input validation and bounds checking mechanisms. Additionally, implementing network segmentation and access controls to limit exposure to potentially malicious Bluetooth dump files can help reduce the risk of exploitation. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage, as attackers may leverage the compromised btmon process to execute malicious code. Regular security assessments and monitoring of Bluetooth-related processes should be implemented to detect potential exploitation attempts and maintain overall system security posture against similar buffer overflow vulnerabilities in wireless communication protocols.