CVE-2022-45192 in RN4870
Summary
by MITRE • 02/08/2023
An issue was discovered on Microchip RN4870 1.43 devices. An attacker within BLE radio range can cause a denial of service by sending a cleartext encryption pause request.
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Analysis
by VulDB Data Team • 03/06/2023
The vulnerability identified as CVE-2022-45192 affects Microchip RN4870 Bluetooth Low Energy devices running firmware version 1.43 and potentially earlier versions. This issue represents a significant security weakness in embedded wireless communication systems that could be exploited by adversaries within physical proximity to target devices. The vulnerability specifically impacts the device's handling of encryption pause requests within the Bluetooth protocol stack, creating a potential pathway for malicious actors to disrupt normal device operations.
The technical flaw manifests when an attacker within Bluetooth radio range transmits a cleartext encryption pause request to the affected device. This particular request type is intended to temporarily suspend encryption during active connections, but the RN4870 device fails to properly validate or handle such requests. The device processes this malformed request without adequate input sanitization or access control verification, leading to a denial of service condition that can effectively disable the device's communication capabilities. This weakness falls under the category of improper input validation as classified by CWE-20, where the system fails to properly validate the integrity and authenticity of incoming protocol messages.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the reliability of connected systems that depend on continuous Bluetooth communication. In industrial IoT deployments, medical devices, or security systems utilizing these chips, such a denial of service attack could result in critical communication failures with potentially serious consequences. The cleartext nature of the attack vector means that no sophisticated cryptographic attacks are required, making the exploit accessible to adversaries with basic Bluetooth reconnaissance capabilities and minimal technical expertise.
This vulnerability aligns with several ATT&CK framework techniques including T1566 for phishing attacks that may involve physical proximity exploitation, and T1499 for network denial of service attacks. The attack surface is particularly concerning for environments where physical security controls are inadequate or where devices are deployed in public spaces where adversaries can easily establish proximity. The lack of encryption verification for pause requests represents a fundamental flaw in the device's security architecture, as it fails to implement proper message authentication mechanisms that would be expected in secure Bluetooth implementations.
Mitigation strategies should focus on immediate firmware updates from Microchip, which would likely include enhanced request validation and proper encryption state management. Network administrators should implement physical security measures to limit unauthorized proximity access to affected devices, particularly in sensitive environments. Additionally, monitoring for unusual Bluetooth traffic patterns and implementing intrusion detection systems specifically tuned to detect anomalous encryption pause request sequences can help identify exploitation attempts. Organizations should also consider network segmentation to limit the potential impact of successful attacks and implement redundant communication paths where critical functionality depends on Bluetooth connectivity. The vulnerability demonstrates the importance of robust input validation in embedded systems and highlights the need for comprehensive security testing of wireless communication protocols before deployment in production environments.