CVE-2021-28831 · cross-distro fix matrix

CVE-2021-28831: 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.

Affects 8 Linux releases across 8 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2021-28831 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

busybox→ fixed in1:1.30.1-6+deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y busybox
```

Debian bookworm

Source: Debian Security Tracker

busybox→ fixed in1:1.35.0-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y busybox
```

Debian trixie

Source: Debian Security Tracker

busybox→ fixed in1:1.35.0-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y busybox
```

Alpine v3.20

Source: Alpine secdb

busybox→ fixed in1.33.0-r5
```
apk update && apk add --upgrade busybox
```

Alpine v3.21

Source: Alpine secdb

busybox→ fixed in1.33.0-r5
```
apk update && apk add --upgrade busybox
```

Alpine edge

Source: Alpine secdb

busybox→ fixed in1.33.0-r5
```
apk update && apk add --upgrade busybox
```

Alpine v3.18

Source: Alpine secdb

busybox→ fixed in1.33.0-r5
```
apk update && apk add --upgrade busybox
```

Alpine v3.19

Source: Alpine secdb

busybox→ fixed in1.33.0-r5
```
apk update && apk add --upgrade busybox
```

Are YOU affected by CVE-2021-28831?

5-second check on your actual server. Reads /etc/os-release, uname -r, and the distro's package manager; matches against this same cross-source index live.

curl https://mindsparkstack.com/scan.sh | bash

Form-based quickscan View on NVD

Continuous monitoring beats manual checking

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