From: matthew-bugtraq () newtoncomputing co uk
[mailto:matthew-bugtraq () newtoncomputing co uk]
Sent: Wednesday, December 15, 2004 3:42 PM
To: Paul Starzetz
Cc: stephen joseph butler; security () isec pl; bugtraq () securityfocus com
Subject: Re: Linux kernel IGMP vulnerabilities
On Wed, Dec 15, 2004 at 01:34:33PM +0100, Paul Starzetz wrote:
On Tue, 14 Dec 2004, stephen joseph butler wrote:
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),
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.
This afternoon I tried the exploit on my machine, which has
exactly those symptoms (data in igmp, mcfilter empty). It
froze solid, hard power-cycle required.