CVE-2021-21703 · cross-distro fix matrix

CVE-2021-21703: In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the ma

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

Fix per ecosystem

Each block below is a distro release where CVE-2021-21703 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

php7.4→ fixed in7.4.25-1+deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y php7.4
```

Alpine v3.18

Source: Alpine secdb

php81→ fixed in8.1.0_rc5-r0
```
apk update && apk add --upgrade php81
```

Alpine v3.19

Source: Alpine secdb

php81→ fixed in8.1.0_rc5-r0
```
apk update && apk add --upgrade php81
```

Are YOU affected by CVE-2021-21703?

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

CVE-2021-21703dropped silently in your distro's update channel. Every new CVE is the same story. StackPatch runs the matcher hourly against all 5 sources and emails the exact remediation when something new applies to one of your servers. $99 lifetime, 50 founder seats, 30-day refund.

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