CVE-2021-34148 : Security Advisory and Response

Bluetooth Classic implementation in Cypress WICED BT stack through 2.9.0 for CYW20735B1 devices allows attackers to trigger a denial of service via a crafted LMP packet.

Understanding CVE-2021-34148

This CVE identifies a vulnerability in the Bluetooth Classic implementation in Cypress WICED BT stack affecting CYW20735B1 devices.

What is CVE-2021-34148?

The vulnerability allows attackers within radio range to exploit the improper handling of LMP_max_slot, leading to a denial of service via a crafted LMP packet.

The Impact of CVE-2021-34148

Attackers can trigger a firmware crash on affected devices, potentially disrupting Bluetooth communications and services.

Technical Details of CVE-2021-34148

The technical details include vulnerability description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

The vulnerability in the Bluetooth Classic implementation allows for a denial of service attack through a crafted LMP packet.

Affected Systems and Versions

All CYW20735B1 devices running Cypress WICED BT stack through version 2.9.0 are affected by this vulnerability.

Exploitation Mechanism

Attackers in radio range can exploit the vulnerability by sending a malicious LMP packet to trigger a firmware crash.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-34148, immediate actions can be taken along with implementing long-term security practices and applying necessary patches and updates.

Immediate Steps to Take

It is recommended to apply vendor-supplied patches or updates to address the vulnerability and protect affected devices.

Long-Term Security Practices

Implementing network segmentation, regularly updating firmware, and monitoring Bluetooth communications can enhance overall security posture.

Patching and Updates

Stay informed about security advisories related to Cypress WICED BT stack and apply patches promptly to prevent exploitation of this vulnerability.