Debian: DSA 102-2 Critical: At Daemon Exploit Severity Issue

Basically, this is the same Security Advisory as DSA 102-1, except
that the uploaded binary packages really fix the problem this time.
Unfortunately the bugfix from DSA 102-1 wasn't propagated properly due
to a packaging bug. While the file parsetime.y was fixed, and
yy.tab.c should be generated from it, yy.tab.c from the original
source was still used. This has been fixed now.

The original advisory said:

zen-parse found a bug in the current implementation of at which leads
into a heap corruption vulnerability which in turn could potentially
lead into an exploit of the daemon user.

This has been fixed in at 3.1.8-10.2 for the stable Debian release and
3.1.8-11 for the unstable and testing release. Packages for unstable
have just been uploaded into . We
recommend that you upgrade your at packages immediately since an
exploit has already been published.

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 manage...