CVE-2021-34144 : Exploit Details and Defense Strategies

Bluetooth Classic implementation in the Zhuhai Jieli AC6366C BT SDK through 0.9.1 is vulnerable to a crafted LMP packet attack, allowing attackers to disrupt BT connections, requiring manual device restart for recovery.

Understanding CVE-2021-34144

This CVE describes a vulnerability in the Bluetooth Classic implementation of Zhuhai Jieli AC6366C BT SDK, allowing attackers to disable new BT connections through a specific LMP packet.

What is CVE-2021-34144?

The vulnerability in Zhuhai Jieli AC6366C BT SDK allows attackers within radio range to disrupt BT connectivity, blocking new connections by sending a specific crafted LMP packet. User intervention through a device restart is necessary to restore connectivity.

The Impact of CVE-2021-34144

This vulnerability poses a risk to devices using Zhuhai Jieli AC6366C BT SDK, potentially leading to a loss of Bluetooth connectivity and disrupting the BT connection process, affecting user experience and connectivity.

Technical Details of CVE-2021-34144

The following technical details outline the vulnerability in Zhuhai Jieli AC6366C BT SDK:

Vulnerability Description

The flaw lies in the improper handling of truncated LMP_SCO_Link_Request packets when no other BT connections are active, enabling attackers to subvert BT connectivity by sending a crafted LMP packet.

Affected Systems and Versions

Zhuhai Jieli AC6366C BT SDK versions 0.9.1 and below are affected by this vulnerability, potentially impacting devices leveraging this specific SDK implementation.

Exploitation Mechanism

Attackers within radio range can exploit this vulnerability by sending a malicious LMP packet, disrupting BT connectivity and preventing new BT connections, rendering the AB5301A inquiry and page scan procedures unusable.

Mitigation and Prevention

To address CVE-2021-34144, users and organizations can take the following steps:

Immediate Steps to Take

Enhance device security protocols and Bluetooth connection monitoring to detect anomalous behavior.
Regularly monitor for security updates and patches from Zhuhai Jieli for AC6366C BT SDK.

Long-Term Security Practices

Implement network segmentation and access controls to limit exposure to potential attackers.
Educate users on recognizing and reporting suspicious Bluetooth activities.

Patching and Updates

Ensure timely application of patches provided by Zhuhai Jieli to address the vulnerability and strengthen BT connectivity security.