CVE-2026-79376 in BES2300 Firmware
Summary
by MITRE • 09/08/2026
An issue in the l2cap_handle_data() function of Bestechnic Co., Ltd BES2300 Bluetooth Audio SoC firmware v3.x and earlier allows attackers to cause a Denial of Service (DoS) via sending a crafted L2CAP packet.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability resides within the l2cap_handle_data() function in the firmware versions 3.x and prior for Bestechnic Co., Ltd BES2300 Bluetooth Audio System on Chip devices. This specific component is responsible for processing Logical Link Control and Adaptation Protocol data packets, which are fundamental to establishing and maintaining connections between Bluetooth peripherals and host systems. The flaw allows remote attackers to trigger a Denial of Service condition by transmitting specially crafted L2CAP packets that exploit improper input validation or boundary checks within the firmware logic. When such malformed packets are received during active communication sessions, they cause the processing routine to fail in an unhandled manner, leading to system instability or complete service interruption for the audio device.
From a technical perspective, this issue aligns with CWE-20 Improper Input Validation and potentially CWE-400 Uncontrolled Resource Consumption if the malformed packet triggers excessive resource allocation before failure. The attack vector is classified under ATT&CK technique T1498 Network Denial of Service, specifically focusing on endpoint disruption through protocol-level exploitation. Since Bluetooth Low Energy and Classic Bluetooth connections are often used for hands-free calling or audio streaming in automotive and consumer electronics environments, the ability to disrupt these services via crafted packets poses a significant operational risk. The attacker does not necessarily need authentication if the device is discoverable or paired with an untrusted entity that can initiate L2CAP connection requests.
The operational impact of this vulnerability extends beyond simple connectivity loss. In automotive infotainment systems utilizing the BES2300, a successful exploit could disable critical safety-related audio alerts such as blind spot warnings or pedestrian detection sounds during driving operations. For consumer headphones and speakers, it results in immediate service degradation where users cannot stream media or make calls until the device is rebooted or reset to factory settings. This disruption affects availability, one of the core pillars of information security confidentiality, integrity, and availability triad. The lack of robust error handling means that a single malicious packet can crash the Bluetooth stack, requiring manual intervention to restore functionality.
Mitigation strategies should prioritize immediate firmware updates provided by Bestechnic Co., Ltd if available for affected versions 3.x and earlier. Organizations deploying these chips in IoT or automotive networks must implement network segmentation to isolate Bluetooth-enabled devices from critical infrastructure segments where possible. Additionally, intrusion detection systems capable of analyzing L2CAP packet structures can be configured to flag anomalous traffic patterns indicative of this exploit attempt. For end-users, disabling discoverability when not actively pairing new devices reduces the attack surface by preventing unauthorized connection attempts that could deliver the crafted packets. Long-term remediation involves enforcing strict input sanitization and state machine validation within future firmware revisions to ensure that malformed L2CAP frames are rejected gracefully without causing system crashes.