🛡️ CVE-2021-42386 on Debian — busybox

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

A use-after-free in Busybox's awk applet leads to denial of service and possibly code execution when processing a crafted awk pattern in the nvalloc function

Distribution advisory

This page covers CVE-2021-42386 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 over the network, attack complexity is low, an attacker needs administrative privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Affected software

DEBIAN-CVE-2021-42386 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-2021-42386 on other distributions

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

Alpine Ubuntu

Details

Severity Unknown

CVSS Score N/A

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

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2021-11-15

Updated 2026-08-12

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-2021-42386

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