Some versions of popper and qpopper from qualcomm allow you to read
other peoples email. There are quite a few situations in which you
need your mail spool directory chmodded 1777. If you have local users
on a machine with the mail spool directory, they can create symbolic
links from the temporary pop drop box to a file that they can read.
See if youre vulnerable:
1) touch /tmp/lumpy; chmod 777 /tmp/lumpy
2) ln -s /tmp/lumpy /var/mail/.luser.pop
3) wait for them to check their email.
4) while they are reading it from the pop
server, look at the file in the tmp dir.
Apparently it is fixed in the newest version.
dynamo