sshd executes ~/.ssh/sshrc without using user's shell

Andrew Bartlett abartlet at pcug.org.au
Wed Mar 21 18:29:56 EST 2001


Markus Friedl wrote:
> 
> On Sat, Mar 17, 2001 at 02:14:22PM +1100, Andrew Bartlett wrote:
> > I am considering allowing (relitivly) untrusted local users onto my
> > fileserver, so they can use SFTP to access their home directories.
> >
> > I have a custom shell, (a taint-mode enabled perl script) that allows
> > users to change their password, which I have modifed to only allow a
> > '-c' command for the sftp-server.
> >
> > I have also disabled TCP port forwarding.  However, some reading of the
> > OpenSSH code suggests that, while most commands sshd excutes use the
> > users login shell, the popen call for .ssh/sshrc does not.
> > (session.c:1342 and there-abouts).
> >
> > Is this an issue?
> 
> yes. in the future, subsystems will probably ignore this file.

Thats good for the subsystems, but as far as I can tell a user with a
restricted shell can still execute arbitary commands, just by not
requesting a subsystem.  Its the arbitary commands buisness that bothers
me.

> 
> > Or do I have bigger things to worry about?
> 
> nothing that i can think of.

Thats good, Thanks

Andrew Bartlett

-- 
Andrew Bartlett
abartlet at pcug.org.au





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