CVE-2021-42717 · cross-distro fix matrix

CVE-2021-42717: ModSecurity 3.x through 3.0.5 mishandles excessively nested JSON objects. Crafted JSON objects with nesting tens-of-thousands deep could result in the web server being unable to service legitimate requests. Even a moderately large (e.g., 300KB) HTTP request can occupy one of the limited NGINX worker

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

Fix per ecosystem

Each block below is a distro release where CVE-2021-42717 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

modsecurity-apache→ fixed in2.9.3-3+deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y modsecurity-apache
```

Debian bookworm

Source: Debian Security Tracker

modsecurity→ fixed in3.0.6-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y modsecurity
```
modsecurity-apache→ fixed in2.9.5-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y modsecurity-apache
```

Debian trixie

Source: Debian Security Tracker

modsecurity→ fixed in3.0.6-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y modsecurity
```
modsecurity-apache→ fixed in2.9.5-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y modsecurity-apache
```

Are YOU affected by CVE-2021-42717?

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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