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

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Message-ID: <4E327148.5030100@redhat.com>
Date: Fri, 29 Jul 2011 16:37:28 +0800
From: Eugene Teo <eugene@...hat.com>
To: oss-security@...ts.openwall.com
CC: Josh Bressers <bressers@...hat.com>, Chris Evans <scarybeasts@...il.com>,
        Greg KH <greg@...ah.com>, Kees Cook <kees@...ntu.com>,
        "Steven M. Christey" <coley@...us.mitre.org>
Subject: Re: CVE Request -- vsftpd -- Do not create network
 namespace per connection

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

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