CVE-2021-3454 : Exploit Details and Defense Strategies

This article provides insights into CVE-2021-3454, a vulnerability in Zephyr affecting versions 2.4.0 and v.2.50.

Understanding CVE-2021-3454

CVE-2021-3454, titled 'Truncated L2CAP K-frame causes assertion failure,' was made public on May 24, 2021.

What is CVE-2021-3454?

The vulnerability in Zephyr versions >= 2.4.0 and >= v.2.50 is related to the Improper Handling of Length Parameter Inconsistency (CWE-130) and Reachable Assertion (CWE-617).

The Impact of CVE-2021-3454

With a CVSS base score of 4.3 (Medium severity), the impact includes an assertion failure triggered by a truncated L2CAP K-frame, potentially leading to security risks.

Technical Details of CVE-2021-3454

Let's dive into the technical aspects of this vulnerability.

Vulnerability Description

The vulnerability arises due to the improper handling of length parameter inconsistency, leading to a reachable assertion issue.

Affected Systems and Versions

Zephyr versions >= 2.4.0 and >= v.2.50 are impacted by this vulnerability.

Exploitation Mechanism

An attacker can exploit this vulnerability by sending a specifically crafted truncated L2CAP K-frame, triggering an assertion failure in the system.

Mitigation and Prevention

Discover the steps to mitigate and prevent the exploitation of CVE-2021-3454.

Immediate Steps to Take

It is recommended to update the affected Zephyr versions to eliminate the vulnerability immediately.

Long-Term Security Practices

Implement secure coding practices and regular security audits to prevent similar vulnerabilities in the future.

Patching and Updates

Stay informed about security patches and updates released by Zephyr to address CVE-2021-3454.