CVE-2018-9481 in Android
Summary
by MITRE • 11/20/2024
In bta_hd_set_report_act of bta_hd_act.cc, there is a possible out-of-bounds read due to an integer overflow. This could lead to remote information disclosure in the Bluetooth service with no additional execution privileges needed. User interaction is not needed for exploitation.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9481 resides within the Bluetooth stack implementation of Google's Android operating system, specifically in the bta_hd_set_report_act function located in the bta_hd_act.cc source file. This flaw represents a critical security weakness that affects the Bluetooth HID (Human Interface Device) subsystem, which handles communication with peripheral devices such as keyboards, mice, and other input devices. The vulnerability manifests as a possible out-of-bounds read condition that stems from improper integer overflow handling within the Bluetooth service layer, making it particularly dangerous as it can be exploited remotely without requiring any additional privileges or user interaction to initiate the attack.
The technical root cause of this vulnerability lies in an integer overflow condition that occurs when processing HID report descriptors during Bluetooth HID device communication. When the Bluetooth HID service receives a malformed report descriptor from a connected device, the integer overflow causes the system to calculate an incorrect buffer size or offset, leading to memory access beyond the intended bounds. This memory access violation can result in information disclosure, where sensitive data from adjacent memory locations may be read and potentially exposed to unauthorized parties. The vulnerability is classified under CWE-190 as an integer overflow or wraparound, which is a well-documented weakness in software systems where arithmetic operations produce values that exceed the maximum representable value for the data type.
The operational impact of CVE-2018-9481 extends beyond simple information disclosure, as it can potentially enable attackers to extract confidential information from the Bluetooth service memory space. This includes but is not limited to authentication credentials, session tokens, device pairing information, and potentially other sensitive system data that may be stored in memory. The remote exploitation capability means that an attacker positioned within Bluetooth range of a vulnerable device can trigger the vulnerability without needing physical access or user interaction, making this a particularly concerning threat vector for mobile devices. The vulnerability affects Android versions prior to 2018, with the exact affected versions including Android 7.0, 7.1, 8.0, and 8.1, and represents a significant risk to mobile device security where Bluetooth connectivity is enabled.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1046 which involves network service scanning and T1059 which covers command and control communication, as the Bluetooth service can be leveraged to establish unauthorized data exfiltration channels. The lack of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited automatically by malicious devices within range, potentially leading to continuous monitoring and data collection without detection. Organizations should implement immediate mitigations including applying the relevant Android security patches, disabling Bluetooth when not in use, and implementing network segmentation to limit potential attack vectors. The vulnerability also highlights the importance of proper input validation and integer overflow protection in embedded systems and mobile operating systems, as similar issues may exist in other Bluetooth stack implementations. Additionally, regular security audits of Bluetooth protocols and services should be conducted to identify and remediate similar vulnerabilities before they can be exploited by threat actors in the wild.