CVE-2021-40426 Memory corruption in libsox

Critical 10.0 Published 14 Apr 2022 Updated 15 Apr 2025

A heap-based buffer overflow in libsox allows attackers to execute arbitrary code or cause denial of service via a specially crafted file.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2021-40426?

CVE-2021-40426 is a critical memory corruption vulnerability in Sound Exchange libsox, published on 14 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A heap-based buffer overflow vulnerability exists in the sphere.c start_read() functionality of Sound Exchange libsox 14.4.2 and master commit 42b3557e. A specially-crafted file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.

Weakness: CWE-787, CWE-122

Which versions are affected by CVE-2021-40426?

It affects 1 product.

Products include Sound Exchange Project Sound Exchange.

How do I fix CVE-2021-40426?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-40426 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-40426 exists.

Sources

Also known as DEBIAN-CVE-2021-40426, GHSA-5x4j-m9qh-g9w5, UBUNTU-CVE-2021-40426.