CVE catalog
CVE-2021-42375
busybox: CVE-2021-42375
- Severity
- Medium · CVSS 4.1
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.41% · Oct 25, 2026
An incorrect handling of a special element in Busybox's ash applet leads to denial of service when processing a crafted shell command, due to the shell mistaking specific characters for reserved characters. This may be used for DoS under rare conditions of filtered command input.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | busybox | sid | 1:1.38.0-3 | fixed |
| Debian | busybox | forky | 1:1.38.0-3 | fixed |
| Debian | busybox | trixie | 1:1.37.0-6 | fixed |
| Debian | busybox | bookworm | 1:1.35.0-4+deb12u1 | fixed |
| Alpine | busybox | 3.13 | 1.32.1-r7 | fixed |
| Alpine | busybox | 3.14 | 1.33.1-r5 | fixed |
| Alpine | busybox | 3.15 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.16 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.17 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.18 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.19 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.20 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.21 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.22 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.23 | 1.34.0-r0 | fixed |
| Alpine | busybox | 3.24 | 1.34.0-r0 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | busybox | source | sid | 1:1.35.0-1 | unimportant | Not reported | [999567] |
| Debian | busybox | source | forky | 1:1.35.0-1 | unimportant | Not reported | [999567] |
| Debian | busybox | source | trixie | 1:1.35.0-1 | unimportant | Not reported | [999567] |
| Debian | busybox | source | bookworm | 1:1.35.0-1 | unimportant | Not reported | [999567] |
| Alpine | busybox | apk | 3.13 | 1.32.1-r7 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.14 | 1.33.1-r5 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.15 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.16 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.17 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.18 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.19 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.20 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.21 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.22 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.23 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
| Alpine | busybox | apk | 3.24 | 1.34.0-r0 | Not reported | ALPINE-CVE-2021-42375 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [busybox]Fixed
Source package: [busybox]
Details (2)
1:1.35.0-4+deb12u1+b1· amd64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
1:1.35.0-4+deb12u1+b1· arm64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
- [busybox-static]Fixed
Source package: [busybox]
Details (2)
1:1.35.0-4+deb12u1+b1· amd64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
1:1.35.0-4+deb12u1+b1· arm64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
- [busybox-syslogd]Fixed
Source package: [busybox]
Details (2)
1:1.35.0-4+deb12u1· all · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
1:1.35.0-4+deb12u1· all · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
- [udhcpc]Fixed
Source package: [busybox]
Details (2)
1:1.35.0-4+deb12u1+b1· amd64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
1:1.35.0-4+deb12u1+b1· arm64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
- [udhcpd]Fixed
Source package: [busybox]
Details (2)
1:1.35.0-4+deb12u1+b1· amd64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
1:1.35.0-4+deb12u1+b1· arm64 · bookwormFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · bookworm; dsa · busybox · debian · 12
[Debian 13 (Trixie)]
- [busybox]Fixed
Source package: [busybox]
Details (2)
1:1.37.0-6+b8· amd64 · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
1:1.37.0-6+b8· arm64 · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
- [busybox-static]Fixed
Source package: [busybox]
Details (2)
1:1.37.0-6+b8· amd64 · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
1:1.37.0-6+b8· arm64 · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
- [busybox-syslogd]Fixed
Source package: [busybox]
Details (2)
1:1.37.0-6· all · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
1:1.37.0-6· all · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
- [udhcpc]Fixed
Source package: [busybox]
Details (2)
1:1.37.0-6· all · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
1:1.37.0-6· all · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
- [udhcpd]Fixed
Source package: [busybox]
Details (2)
1:1.37.0-6· all · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
1:1.37.0-6· all · trixieFixed · Fixed:
1:1.35.0-1dsa · busybox · debian · 13
Observed:
References
- [https://cert-portal.siemens.com/productcert/csaf/ssa-419740.json]
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2022_0135-1.json]
- [https://osv.dev/vulnerability/ALPINE-CVE-2021-42375]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2021-42375]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2021-42375]
- [https://security-tracker.debian.org/tracker/CVE-2021-42375]
- [https://wid.cert-bund.de/.well-known/csaf/white/2021/wid-sec-w-2022-2028.json]
[CERT-Bund public advisories] · [CISA cybersecurity advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]