Re: CVE Request -- vsftpd -- Do not create network namespace per connection

[Eugene Teo <eugene () redhat com>]

On 06/07/2011 02:28 AM, Josh Bressers wrote:
> ----- Original Message -----
> > Hello, Josh, Steve, vendors,
> >
> > It was found that vsftpd, Very Secure FTP daemon, when the network
> > namespace (CONFIG_NET_NS) support was activated in the kernel, used to
> > create a new network namespace per connection. A remote attacker could
> > use this flaw to cause a memory pressure and denial of the vsftpd
> > service.
> >
> > References:
> > [1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=629373
> > [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/720095
> > [3] https://bugzilla.redhat.com/show_bug.cgi?id=711134
> >
> > This one being a bit tricky one -- from my understanding of the issue,
> > vsftpd doesn't necessarily have a security flaw on its side. It's
> > kernel issue / bug, which allows this to be used for vsftpd DoS:
> > [4]
> > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/720095/comments/31
> > [5]
> > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/720095/comments/32
> >
> > Short-term solution would be probably to address this on the vsftpd
> > side, the long-term one then being to get this fixed in kernel.
> >
> > Though not sure, how it would be wrt to CVE identifier(s) assignment.
>
> I'm going to assign CVE-2011-2189 for the kernel. There are numerous
> vendors shipping this bug.
>
> I'll leave it up to MITRE if they think vsftpd should get an ID. I don't
> think it should myself, but they understand these corner cases better than
> I.

Kees, how are you guys fixing this? Disable net_ns and fix vsftpd? I
wonder how other distros approach this. Any suggestions?

Thanks, Eugene