CVE-2021-3329 : Exploit Details and Defense Strategies

A detailed overview of CVE-2021-3329, a vulnerability in the HCI Host stack initialization that can lead to a crash of the bluetooth stack.

Understanding CVE-2021-3329

In this section, we will explore what CVE-2021-3329 is, its impact, technical details, and mitigation strategies.

What is CVE-2021-3329?

The CVE-2021-3329 vulnerability involves improper validation in the HCI Host stack initialization, potentially resulting in a crash of the bluetooth stack.

The Impact of CVE-2021-3329

The impact of this vulnerability is severe, with a CVSS base score of 9.6 (Critical). It can lead to a denial of service (DOS) scenario, affecting the availability and integrity of the bluetooth host layer.

Technical Details of CVE-2021-3329

Let's delve into the technical specifics of CVE-2021-3329, including the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The lack of proper validation in the HCI Host stack initialization can be exploited to trigger a crash of the bluetooth stack, causing a denial of service.

Affected Systems and Versions

The vulnerability affects the zephyr project RTOS with versions up to v2.4, impacting systems where this specific version is utilized.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending specially crafted packets during the HCI ACL_MTU handshake, leading to a crash of the bluetooth host layer.

Mitigation and Prevention

To address CVE-2021-3329, immediate steps must be taken to secure systems, along with long-term security practices and patching procedures.

Immediate Steps to Take

Implement network segmentation, apply the latest patches, and monitor network traffic for any suspicious activities to mitigate the risk associated with this vulnerability.

Long-Term Security Practices

Regularly update system components, conduct security training for personnel, and perform periodic security assessments to enhance overall security posture.

Patching and Updates

Ensure that patches provided by the vendor, in this case zephyrproject-rtos, are promptly applied to vulnerable systems to remediate the CVE-2021-3329 vulnerability.