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Re: how do I use UID setting?



Miquel van Smoorenburg:
> Simple - setuid shell scripts are not supported under Linux because we
> have learned from history that it is impossible to create a secure shell
> script.

That's not the reason.

The reason is that the semantics of the #! line have the script passed to
the shell by name. In the meantime, a hacker can substitute a different
script. Making the directory unwriteable doesn't help, as the script can be
hardlinked to.

Solving this requires changing the semantics of either suid or #! - the
former is done by sudo (which does suid-by-pathname), the latter in systems
where the script is passed to the shell via an open handle.


Jiri
-- 
<jiri@baum.com.au>
We'll know the future has arrived when every mailer transparently
quotes lines that begin with "From ", but no-one remembers why.


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