From: "Henderson, Michael D" <michael.d.henderson@...>
Date: 2002-09-12T08:51:00+09:00
Subject: RE: RubyInline 1.0.4 Released! (fwd)

Assume that the executable is in /home/foo/bar/boof and I have write
permissions on /home/foo (either group or world).

I can rename foo (eg, mv /home/foo /home/.foo) and create a new foo
directory that I own and a /home/foo/bar directory, too.

Now I can selectively copy the items from bar on down back in to my new
directory, changing those items that need it and setting
permissions/owner/group as needed to fool you into thinking that nothing's
wrong.

That's why a group writable home directory is bad. I can go in and create a
.rhosts file that allows me to become you, and get you in trouble.

Mike

-----Original Message-----
From: bbense+comp.lang.ruby.Sep.11.02@telemark.stanford.edu

- - To be honest I don't quite understand the specific mechanisms by which a
group
writeable directory anywhere in the tree can be abused, but all the really
paranoid software I know of takes this precaution.