CVE-2021-3434 : Exploit Details and Defense Strategies

A stack-based buffer overflow vulnerability was discovered in Zephyr versions greater than or equal to v2.5.0, affecting the le_ecred_conn_req() function.

Understanding CVE-2021-3434

This CVE highlights a critical security issue in the Zephyr RTOS, potentially leading to unauthorized access and system compromise.

What is CVE-2021-3434?

The vulnerability involves a stack-based buffer overflow in the le_ecred_conn_req() function within Zephyr versions >= v2.5.0, classified as CWE-121.

The Impact of CVE-2021-3434

With a CVSS base score of 4.9 (Medium severity), the vulnerability could allow an attacker to execute arbitrary code or crash the application.

Technical Details of CVE-2021-3434

This section delves into the specifics of the vulnerability.

Vulnerability Description

The issue stems from a stack-based buffer overflow in the le_ecred_conn_req() function, increasing the risk of exploitation.

Affected Systems and Versions

Zephyr versions >= v2.5.0 and < v2.6.0 are confirmed to be impacted by this vulnerability.

Exploitation Mechanism

An attacker can exploit this vulnerability by crafting a malicious request, triggering the buffer overflow and potentially gaining unauthorized access.

Mitigation and Prevention

Addressing this vulnerability is crucial to maintaining system security.

Immediate Steps to Take

Update Zephyr to version v2.6.0 or higher to eliminate this vulnerability.
Implement security best practices to reduce the risk of buffer overflow attacks.

Long-Term Security Practices

Regularly monitor security advisories and update systems promptly to mitigate potential risks.

Patching and Updates

Stay informed about security patches released by Zephyr and apply them as soon as they are available, ensuring a secure system.