Debian: DSA-2021-2 Critical: Fix For Spamass-Milter Input Flaw

The latest DSA for spamass-milter introduced a regression: when running
spamass-milter with -x, a zombie process is left around for every mail
received. This update corrects this problem.
For reference, the original advisory text is provided below.

It was discovered a missing input sanitization in spamass-milter, a milter
used to filter mail through spamassassin.
This allows a remote attacker to inject and execute arbitrary shell commands.

For the stable distribution (lenny), this problem has been fixed in
version 0.3.1-8+lenny2.

For the testing (squeeze) and unstable (sid) distribution this problem
has been fixed in version 0.3.1-9.

We recommend that you upgrade your spamass-milter package.

Upgrade instructions
- --------------------

wget url
will fetch the file for you
dpkg -i file.deb
will install the referenced file.

If you are using the apt-get package manager, use the line for
sources.list as given below:

apt-get update
will update the internal database
apt-get upgrade
...