CVE-2021-38509 · cross-distro fix matrix

CVE-2021-38509: Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Affects 8 Linux releases across 23 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2021-38509 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

firefox-esr→ fixed in91.4.1esr-1~deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y firefox-esr
```
thunderbird→ fixed in1:91.4.1-1~deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y thunderbird
```

Debian bookworm

Source: Debian Security Tracker

firefox-esr→ fixed in91.3.0esr-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y firefox-esr
```
thunderbird→ fixed in1:91.3.0-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y thunderbird
```

Debian trixie

Source: Debian Security Tracker

firefox-esr→ fixed in91.3.0esr-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y firefox-esr
```
thunderbird→ fixed in1:91.3.0-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y thunderbird
```

Alpine v3.20

Source: Alpine secdb

firefox-esr→ fixed in91.3.0-r0

apk update && apk add --upgrade firefox-esr

firefox→ fixed in94.0-r0
```
apk update && apk add --upgrade firefox
```

thunderbird→ fixed in91.3.2-r0

apk update && apk add --upgrade thunderbird

Alpine v3.21

Source: Alpine secdb

firefox-esr→ fixed in91.3.0-r0

apk update && apk add --upgrade firefox-esr

firefox→ fixed in94.0-r0
```
apk update && apk add --upgrade firefox
```

librewolf→ fixed in94.0-r0

apk update && apk add --upgrade librewolf

thunderbird→ fixed in91.3.2-r0

apk update && apk add --upgrade thunderbird

Alpine edge

Source: Alpine secdb

firefox-esr→ fixed in91.3.0-r0

apk update && apk add --upgrade firefox-esr

firefox→ fixed in94.0-r0
```
apk update && apk add --upgrade firefox
```

librewolf→ fixed in94.0-r0

apk update && apk add --upgrade librewolf

thunderbird→ fixed in91.3.2-r0

apk update && apk add --upgrade thunderbird

Alpine v3.18

Source: Alpine secdb

firefox-esr→ fixed in91.3.0-r0

apk update && apk add --upgrade firefox-esr

firefox→ fixed in94.0-r0
```
apk update && apk add --upgrade firefox
```

thunderbird→ fixed in91.3.2-r0

apk update && apk add --upgrade thunderbird

Alpine v3.19

Source: Alpine secdb

firefox-esr→ fixed in91.3.0-r0

apk update && apk add --upgrade firefox-esr

firefox→ fixed in94.0-r0
```
apk update && apk add --upgrade firefox
```

thunderbird→ fixed in91.3.2-r0

apk update && apk add --upgrade thunderbird

Are YOU affected by CVE-2021-38509?

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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