CVE-2021-4120 · cross-distro fix matrix

CVE-2021-4120: snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the ability for snaps to inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and hence escape strict snap confinement. Fixed in snapd versions 2.54.

Affects 3 Linux releases across 3 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2021-4120 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

snapd→ fixed in2.49-1+deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y snapd
```

Debian bookworm

Source: Debian Security Tracker

snapd→ fixed in2.54.3-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y snapd
```

Debian trixie

Source: Debian Security Tracker

snapd→ fixed in2.54.3-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y snapd
```

Are YOU affected by CVE-2021-4120?

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

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