CVE-2021-28831: Busybox

High severity, CVSS 7.5. EPSS: 2.7% chance of exploitation in the next 30 days.

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 Busybox: from 1.32.0, up to and including 1.32.1
• Debian Debian Linux: version 9.0 only
• Fedoraproject Fedora: version 32 only; version 33 only; version 34 only

Published 2021-03-19. Last modified 2026-06-17.