🛡️ CVE-2021-42376 on Debian — busybox

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

A NULL pointer dereference in Busybox's hush applet leads to denial of service when processing a crafted shell command, due to missing validation after a \x03 delimiter character. This may be used for DoS under very rare conditions of filtered command input.

Distribution advisory

This page covers CVE-2021-42376 as tracked by Debian, for the package busybox. The fix is available in version 1:1.35.0-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software

DEBIAN-CVE-2021-42376 is recorded against 1 package.

busybox (fixed in 1:1.35.0-1)

Timeline and source

Published on 15 November 2021 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2021-42376 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Alpine

Details

Severity Unknown

CVSS Score N/A

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2021-11-15

Updated 2026-08-20

Modified 2026-08-04

Fix URL N/A

Affected Packages

Software	From version	Fixed in
busybox	—	1:1.35.0-1

References

ADVISORY https://security-tracker.debian.org/tracker/CVE-2021-42376

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