Mailing the story:
Debian alert: New mozart packages fix unsafe mailcap configuration
mozart, a development platform based on the Oz language, includes MIME
configuration data which specifies that Oz applications should be
passed to the Oz interpreter for execution. This means that file
managers, web browsers, and other programs which honor the mailcap
file could automatically execute Oz programs downloaded from untrusted
sources. Thus, a malicious Oz program could execute arbitrary code
under the uid of a user running a MIME-aware client program if the
user selected a file (for example, choosing a link in a web browser).