CVE-2024-7138 in RS9116 Bluetooth SDK
Summary
by MITRE • 12/19/2024
An assert may be triggered, causing a temporary denial of service when a peer device sends a specially crafted malformed L2CAP packet. If a watchdog timer is not enabled, a hard reset is required to recover the device.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/29/2025
This vulnerability resides within the Bluetooth Low Energy stack implementation where a malformed Layer 2 Control and Adaption Protocol packet can trigger an assertion failure leading to temporary denial of service conditions. The flaw specifically manifests when a peer device transmits a carefully crafted L2CAP packet that violates expected protocol boundaries or contains unexpected parameter values. The assertion mechanism, designed to detect invalid states during protocol processing, fails to handle such malformed inputs gracefully, resulting in immediate termination of the affected process or thread. This behavior directly impacts the device's ability to maintain stable Bluetooth connections and process legitimate communication requests.
The technical implementation of this vulnerability demonstrates a classic lack of input validation within the Bluetooth protocol stack's L2CAP layer processing code. When the malformed packet reaches the processing pipeline, the system's assertion mechanism evaluates conditions that should never occur under normal circumstances, but due to the crafted nature of the input, these conditions are met. This assertion failure typically occurs during packet parsing or parameter validation phases where the system expects specific data formats or ranges that are violated by the malicious input. The absence of proper error handling or graceful degradation mechanisms means that the system cannot continue normal operations after encountering such malformed data.
From an operational perspective, this vulnerability presents a significant risk to devices that rely on continuous Bluetooth connectivity for critical functions, particularly those in industrial IoT environments, medical devices, or automotive systems where temporary service interruption could lead to safety concerns or operational failures. The impact extends beyond simple disruption as the vulnerability may require manual intervention to restore system functionality, especially when watchdog timers are not properly configured or enabled. In environments where automatic recovery mechanisms are absent, administrators must manually perform hard resets, which can result in extended downtime and potential data loss. The vulnerability affects the availability aspect of the security triad by creating temporary service unavailability that can persist until manual intervention occurs.
The vulnerability aligns with CWE-617, which addresses reachable assertions in software systems, and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for Network Denial of Service attacks. Organizations should implement robust input validation mechanisms at all protocol layers to prevent malformed packets from reaching assertion points. The recommended mitigations include enabling watchdog timers to automatically recover from assertion failures, implementing proper error handling procedures that allow graceful degradation rather than complete system termination, and deploying network monitoring solutions to detect and potentially block malformed L2CAP traffic patterns. Additionally, regular firmware updates should be applied to address the underlying implementation flaws, and system administrators should consider implementing network segmentation to limit the impact of such attacks on critical infrastructure components.