Hi Paul,
Facts :
- Several distributions run with vulnerable settings per default
if there is a "misconfiguration" it is part of the vendor.
- Your not supposed to be able to traverse dirs.
Consequence it is a vulnerability, whether you can mitigate it is
a different piece of cake.
Next time somebody creates an IE8 0day that relies on javascript,
will you scream "misconfiguration!" ? Of course you could disable
javascript but is it by enabled default ? Yes.
The question for smb is who does restrict this setting?
My tests reveal - not many.
Congrats Kingcope, nice bug. Directory traversal in major daemon in
2010.
Regards,
Thierry
pssea> Dear Kingcope,
pssea> The samba server follows symlinks by default. There are options
pssea> ("follow symlinks", "wide links") for turning it off:
pssea> http://www.samba.org/samba/docs/using_samba/ch08.html#samba2-CHP-8-SECT-1.2
pssea> http://www.samba.org/samba/docs/man/manpages-3/smb.conf.5.html#FOLLOWSYMLINKS
pssea> http://www.samba.org/samba/docs/man/manpages-3/smb.conf.5.html#WIDELINKS
pssea> The "problem" at your installation seems a mis-configuration of
pssea> your server: please ask the admin to set "secure" options.
pssea> (Some samba installations, like mine, wish to allow same access as a
pssea> UNIX login would allow. Some shares like [home] are provided for ease
pssea> of use, users are encouraged to create symlinks to other "interesting"
pssea> places e.g. NFS-mounted directories.)
pssea> Cheers, Paul
pssea> Paul Szabo psz@xxxxxxxxxxxxxxxxx
pssea> http://www.maths.usyd.edu.au/u/psz/
pssea> School of Mathematics and Statistics University of Sydney Australia
pssea> _______________________________________________
pssea> Full-Disclosure - We believe in it.
pssea> Charter: http://lists.grok.org.uk/full-disclosure-charter.html
pssea> Hosted and sponsored by Secunia - http://secunia.com/
--
http://blog.zoller.lu
Thierry Zoller
