I just finished a blog post detailing how the popular text editor,
nano, is unsafe to run as root to edit untrusted users' files, with
consequences including full privilege escalation:

http://drosenbe.blogspot.com/2010/03/nano-as-root.html 

This is not a disclosure of vulnerabilities per se; rather, it's just
a look at how some security assumptions may not hold when running
programs as root in a hostile environment, using nano as an example.
Nothing earth-shattering, just thought some of you might be
interested.  Comments welcome.

-Dan