What’s Vulnerable › Vulnerabilities

CVE-2021-28831

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-03-19 · updated 2026-06-17
• Weakness: CWE-755

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.

Affected products

• busybox: from 1.32.0 through 1.32.1
• Debian Linux: 9.0
• Fedoraproject Fedora: 32, 33, 34

References

• https://git.busybox.net/busybox/commit/?id=f25d254dfd4243698c31a4f3153d4ac72aa9e9bd
• https://lists.debian.org/debian-lts-announce/2021/04/msg00001.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UDQGJRECXFS5EZVDH2OI45FMO436AC4/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7ZIFKPRR32ZYA3WAA2NXFA3QHHOU6FJ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZASBW7QRRLY5V2R44MQ4QQM4CZIDHM2U/
• https://security.gentoo.org/glsa/202105-09
• https://git.busybox.net/busybox/commit/?id=f25d254dfd4243698c31a4f3153d4ac72aa9e9bd
• https://lists.debian.org/debian-lts-announce/2021/04/msg00001.html
• https://lists.debian.org/debian-lts-announce/2025/01/msg00012.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UDQGJRECXFS5EZVDH2OI45FMO436AC4/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7ZIFKPRR32ZYA3WAA2NXFA3QHHOU6FJ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZASBW7QRRLY5V2R44MQ4QQM4CZIDHM2U/

Get alerted when CVE-2021-28831 or the next vulnerability affects your stack