CVE-2023-42365 Use after free in n/a

Medium 5.5 Published 27 Nov 2023 Updated 3 Nov 2025

Attackers can trigger a use-after-free in BusyBox awk via crafted patterns, potentially leading to code execution or crashes.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2023-42365?

CVE-2023-42365 is a medium-severity use after free vulnerability in n/a, published on 27 Nov 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

A use-after-free vulnerability was discovered in BusyBox v.1.36.1 via a crafted awk pattern in the awk.c copyvar function.

Weakness: CWE-416

Which versions are affected by CVE-2023-42365?

It affects 1 product.

Products include Busybox Busybox.

How do I fix CVE-2023-42365?

Upgrade to a fixed version.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2023-42365 being exploited?

There is no known exploitation of CVE-2023-42365 in the wild and no public exploit code.

Sources

Also known as ALPINE-CVE-2023-42365, AZL-33494, AZL-34576, BELL-CVE-2023-42365, CLEANSTART-2026-PZ89889, DEBIAN-CVE-2023-42365 and 3 more.