Vulnerability · Published Nov 15, 2021 · Assigned by JFROG
CVE-2021-42386
High 7.2
In plain English
A high-severity use-after-free in busybox from busybox. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.7% (higher than 86% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.2High
Exploit odds (30 days)2.7%top 13.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | busybox | 1.34.0-r0 | ALPINE-CVE-2021-42386 |
| Alpine:v3.21 | busybox | 1.34.0-r0 | ALPINE-CVE-2021-42386 |
| Alpine:v3.22 | busybox | 1.34.0-r0 | ALPINE-CVE-2021-42386 |
| Alpine:v3.23 | busybox | 1.34.0-r0 | ALPINE-CVE-2021-42386 |
| Alpine:v3.24 | busybox | 1.34.0-r0 | ALPINE-CVE-2021-42386 |
| Debian:12 | busybox | 1:1.35.0-1 | DEBIAN-CVE-2021-42386 |
| Debian:13 | busybox | 1:1.35.0-1 | DEBIAN-CVE-2021-42386 |
| Debian:14 | busybox | 1:1.35.0-1 | DEBIAN-CVE-2021-42386 |
| Ubuntu:22.04:LTS | busybox | 1:1.30.1-7ubuntu2 | UBUNTU-CVE-2021-42386 |
Affected products (as reported)
Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
References
- https://jfrog.com/blog/unboxing-busybox-14-new-vulnerabilities-uncovered-by-claroty-and-jfrog/
- FEDORA-2021-5a95823596 vendor-advisory
- FEDORA-2021-c52c0fe490 vendor-advisory
- https://security.netapp.com/advisory/ntap-20211223-0002/
- https://claroty.com/team82/research/unboxing-busybox-14-vulnerabilities-uncovered-by-claroty-jfrog
- https://lists.debian.org/debian-lts-announce/2025/01/msg00012.html