CVE-2021-21408 · cross-distro fix matrix

CVE-2021-21408: Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.43 and 4.0.3, template authors could run restricted static php methods. Users should upgrade to version 3.1.43 or 4.0.3 to receive a patch.

Affects 3 Linux releases across 5 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2021-21408 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

smarty3→ fixed in3.1.39-2+deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y smarty3
```

Debian bookworm

Source: Debian Security Tracker

smarty3→ fixed in3.1.45-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y smarty3
```
smarty4→ fixed in4.1.1-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y smarty4
```

Debian trixie

Source: Debian Security Tracker

smarty3→ fixed in3.1.45-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y smarty3
```
smarty4→ fixed in4.1.1-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y smarty4
```

Are YOU affected by CVE-2021-21408?

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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