[Simon Walter] Re: Bug#506353: mailscanner: many scripts allow local users to overwrite arbitrary files, and more, via symlink attacks

[Matt]

Julian Field wrote:
> Well if you can even give me a definitive statement of precisely what 
> the underlying theoretical problem is, and how to avoid it, that would 
> help. I don't want to write a load of code and then discover I've 
> misunderstood the underlying problem and not actually fixed anything. 

http://lists.debian.org/debian-devel/2008/08/msg00285.html

The above is the message that starts it all.  Basically because the auto 
updaters create temporary files in /tmp it is theoretically possible for 
a user to create a symlink to another file and compromise the system.

matt