CVE-2021-28831: busybox
CVSS: 7.5v3.1HighModified
AliasesALPINE-CVE-2021-28831MGASA-2021-0310UBUNTU-CVE-2021-28831USN-5179-2DEBIAN-CVE-2021-28831DLA-2614-1
Published 19-03-2021Last modified 17-12-2025
Vulnerability summary
CVE-2021-28831 is a high (CVSS 7.5) vulnerability in busybox. EPSS estimates a 2.72% chance of exploitation in the next 30 days, higher than 85.8% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
2.72%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 12 · Related 11Timeline
- 19-03-2021PublishedVulnerability first disclosed.
- 17-12-2025Last modifiedVulnerability information updated.
Description
decompress_gunzip.c in BusyBox through 1.32.1 mishandles the error bit on the huft_build result pointer, with a resultant invalid free or segmentation fault, via malformed gzip data.
CVSS metrics
6 scores · 5 sources · 2 versionsHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:N/S:U/UI:NSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
2.72%
Chance of exploitation in the next 30 days
Percentile
86%
Versus all other CVEs
30-day change
0.00 pp
From 2.72% on 18-09-2026
18-09-202618-10-2026
EPSS score2.72%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- busybox< 1:1.35.0-1 | < 1:1.22.0-19+deb9u2
- debian_linuxEOL9.0
Mageia2 products
- busybox< 1.30.1-1.2.mga7
- busybox< 1.32.1-1.1.mga8
Alpine1 product
- busybox≥ 1.32.0, < 1.30.1-r5 | ≥ 1.32.0, < 1.31.1-r10 | ≥ 1.32.0, < 1.31.1-r20 | ≥ 1.32.0, < 1.32.1-r4 | ≥ 1.32.0, < 1.33.0-r5
Busybox1 product
- busybox≥ 1.32.0, ≤ 1.32.1
Fedoraproject1 product
- fedoraEOL32 | 33 | 34
Ubuntu1 product
- busybox< 1:1.22.0-15ubuntu1.4+esm1 | < 1:1.21.0-1ubuntu1.4+esm1 | < 1:1.27.2-2ubuntu3.4 | < 1:1.30.1-4ubuntu6.4 | < 1:1.30.1-7ubuntu2
6 vendors · 8 products
References
19 links- git.busybox.net/busybox/commit/?id=f25d254dfd4243698c31a4f3153d4ac72aa9e9bdX Refsource MISCMailing ListPatchVendor Advisory
lists.debian.org/debian-lts-announce/2021/04/msg00001.htmlMailing ListX Refsource MLISTThird Party Advisory
