CVE-2021-42385 : What You Need to Know

A use-after-free vulnerability in Busybox's awk applet can result in denial of service and potential code execution.

Understanding CVE-2021-42385

What is CVE-2021-42385?

This CVE describes a use-after-free vulnerability in Busybox's awk applet, leading to denial of service and potential code execution when processing a malicious awk pattern.

The Impact of CVE-2021-42385

The vulnerability can be exploited to cause a denial of service condition and may allow an attacker to execute arbitrary code on affected systems.

Technical Details of CVE-2021-42385

Vulnerability Description

The use-after-free vulnerability occurs in Busybox's awk applet during the processing of a crafted awk pattern in the evaluate function.

Affected Systems and Versions

Vendor: Busybox
Product: Busybox
Affected Versions: Versions prior to 1.34.0

Exploitation Mechanism

The vulnerability can be exploited by an attacker sending a specially crafted awk pattern to the vulnerable application, leveraging the use-after-free condition to trigger the denial of service or potential code execution.

Mitigation and Prevention

Immediate Steps to Take

Apply the latest security patches provided by Busybox promptly.
Monitor vendor advisories and security mailing lists for updates.
Restrict network access to vulnerable systems.

Long-Term Security Practices

Regularly update and patch all software and libraries in the environment.
Implement least privilege access controls to limit the impact of potential exploits.

Patching and Updates

Update Busybox to version 1.34.0 or later to mitigate the vulnerability and enhance the security of the system.