CVE-2021-21424 · cross-distro fix matrix

CVE-2021-21424: Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We

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

Fix per ecosystem

Each block below is a distro release where CVE-2021-21424 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

symfony→ fixed in4.4.19+dfsg-2urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y symfony
```

Debian bookworm

Source: Debian Security Tracker

symfony→ fixed in4.4.19+dfsg-2urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y symfony
```

Debian trixie

Source: Debian Security Tracker

symfony→ fixed in4.4.19+dfsg-2urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y symfony
```

Are YOU affected by CVE-2021-21424?

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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