CVE-2022-31363 in Bluetooth Mesh SDK
Summary
by MITRE • 02/01/2023
Cypress : https://www.infineon.com/ Cypress Bluetooth Mesh SDK BSA0107_05.01.00-BX8-AMESH-08 is affected by: Buffer Overflow. The impact is: execute arbitrary code (remote). The component is: affected function is pb_transport_handle_frag_. ¶¶ In Cypress Bluetooth Mesh SDK, there is an out-of-bound write vulnerability that can be triggered during mesh provisioning. Because there is no check for mismatched SegN and TotalLength in Transaction Start PDU.
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Analysis
by VulDB Data Team • 03/28/2025
The vulnerability identified as CVE-2022-31363 affects the Cypress Bluetooth Mesh SDK version BSA0107_05.01.00-BX8-AMESH-08 and represents a critical buffer overflow flaw that enables remote code execution. This vulnerability resides within the pb_transport_handle_frag_ function, which processes fragmented data during Bluetooth mesh provisioning operations. The flaw stems from insufficient validation of transaction parameters, specifically failing to verify the consistency between SegN (segment number) and TotalLength fields in the Transaction Start PDU. This omission creates a condition where an attacker can craft malicious packets that cause out-of-bounds memory writes, potentially allowing arbitrary code execution on affected devices. The vulnerability is particularly concerning because Bluetooth mesh networks operate in environments where devices may be exposed to untrusted network traffic, making remote exploitation feasible without requiring physical access or authentication.
The technical implementation of this vulnerability demonstrates a classic buffer overflow condition classified under CWE-121, which occurs when insufficient bounds checking allows data to be written beyond the allocated buffer boundaries. During mesh provisioning, the system expects to receive fragmented data packets that must be reassembled correctly. However, the pb_transport_handle_frag_ function does not validate that the SegN value aligns with the TotalLength parameter, allowing attackers to manipulate these values to overwrite adjacent memory locations. This memory corruption can lead to unpredictable behavior including program crashes, data corruption, or more critically, the execution of attacker-controlled code. The vulnerability affects the core transport layer functionality of the Bluetooth mesh stack, making it a fundamental weakness in the device's security architecture.
From an operational perspective, this vulnerability poses significant risks to Bluetooth mesh network deployments, particularly in industrial IoT environments where these devices are commonly used for sensor networks, lighting control, and building automation systems. The remote exploitation capability means that attackers can target devices from outside the physical network boundary, potentially compromising entire mesh networks if multiple devices are vulnerable. The impact extends beyond individual device compromise to potential network-wide disruption, as mesh networks rely on interconnected devices that can relay messages and commands throughout the system. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically through the execution of arbitrary code, and represents a critical weakness in the network's defensive posture against remote attacks. Organizations deploying Bluetooth mesh solutions must consider this vulnerability as a high-priority risk requiring immediate attention.
Mitigation strategies for CVE-2022-31363 should include immediate firmware updates from Cypress to address the buffer overflow in the pb_transport_handle_frag_ function. Network administrators should implement network segmentation and monitoring to detect anomalous provisioning traffic patterns that might indicate exploitation attempts. The vulnerability also highlights the importance of input validation and bounds checking in embedded systems, particularly those handling network protocols. Organizations should conduct thorough vulnerability assessments of their Bluetooth mesh deployments to identify all potentially affected devices and ensure proper patch management procedures are in place. Additionally, implementing network access controls and limiting provisioning access to trusted networks can help reduce the attack surface, while regular security audits of mesh network configurations can help identify and remediate similar implementation flaws in other components of the system.