Re: Samba symlink 0day flaw

[Michael Gilbert <michael.s.gilbert () gmail com>]

On Fri, 5 Feb 2010 22:05:30 +0100, Nico Golde wrote:
> Hey,
> * Josh Bressers <bressers () redhat com> [2010-02-05 20:11]:
> > As many of you have probably seen, there was a supposed Samba 0day flaw
> > posted to full-disclosure and youtube.
> >
> > Samba has a response to this:
> > http://marc.info/?l=samba-technical&m=126539387432412&w=2
> >
> > I'm not sure if this should get a CVE id. It is documented behavior.
> > Somewhat unexpected though. I think changing the default is the right way
> > to go, but it may be more of a hardening measure than a security fix.
> >
> > Thoughts Steve?
>
> Given the count of users that are probably affected by this and it not being 
> documented in e.g. man 5 smb.conf I'd vote for yes! :)

i think this should get a CVE.  "wide links = no" is not really a
hardening feature.  it is a solution for a certain subset of samba
users [0].  many will need to set "wide links = yes" (in order to
use symlinks to local files) and will remain vulnerable.

besides, the Confidentiality Impact and Integrity Impact are rather
high since pretty much any file on the victim's system can be read 
(confidentiality) and /tmp and other locations are writeable
(integrity).

mike

[0] http://lists.samba.org/archive/samba-technical/2010-February/069196.html