Re: Linux kernel IGMP vulnerabilities

[Paul Starzetz <ihaquer@xxxxxxx>]

On Tue, 14 Dec 2004, stephen joseph butler wrote:

> > /proc/net/igmp
> > /proc/net/mcfilter
> > 
> > if both exist and are non-empty you are vulnerable!
> 
> Just to be clear: if "mcfilter" is empty, then you aren't vulnerable?
> I have both files, and "igmp" contains data, but "mcfilter" is empty.

You are not vulnerable to the remote attack described under (3), however 
your kernel may be still buggy. Note that you need a running process that 
has manipulated its multicast socket filters. If your kernel is buggy and 
you have local users such an application can always appear, at a time you 
don't expect it.

-- 
Paul Starzetz
iSEC Security Research
http://isec.pl/