CVE-2021-33913 · cross-distro fix matrix

CVE-2021-33913: libspf2 before 1.2.11 has a heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of SPF_record_expand_data in spf_expand.c. The amount of overflowed data dep

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

Fix per ecosystem

Each block below is a distro release where CVE-2021-33913 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

libspf2→ fixed in1.2.10-7.1~deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y libspf2
```

Debian bookworm

Source: Debian Security Tracker

libspf2→ fixed in1.2.10-7.1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y libspf2
```

Debian trixie

Source: Debian Security Tracker

libspf2→ fixed in1.2.10-7.1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y libspf2
```

Alpine v3.20

Source: Alpine secdb

libspf2→ fixed in1.2.11-r0
```
apk update && apk add --upgrade libspf2
```

Alpine v3.21

Source: Alpine secdb

libspf2→ fixed in1.2.11-r0
```
apk update && apk add --upgrade libspf2
```

Alpine edge

Source: Alpine secdb

libspf2→ fixed in1.2.11-r0
```
apk update && apk add --upgrade libspf2
```

Alpine v3.18

Source: Alpine secdb

libspf2→ fixed in1.2.11-r0
```
apk update && apk add --upgrade libspf2
```

Alpine v3.19

Source: Alpine secdb

libspf2→ fixed in1.2.11-r0
```
apk update && apk add --upgrade libspf2
```

Are YOU affected by CVE-2021-33913?

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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