Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Fri, 28 Feb 2014 11:46:24 -0800
From: Chris Steipp <csteipp@...imedia.org>
To: oss-security@...ts.openwall.com
Cc: cve-assign@...re.org, mmcallis@...hat.com, 
	Markus Glaser <glaser@...lowelt.biz>
Subject: Re: CVE requests: MediaWiki 1.22.3, 1.21.6 and 1.19.12 release

I'm from the foundation, and I'm on the list. Let me try to answer.

On Feb 28, 2014 10:55 AM, "Vincent Danen" <vdanen@...hat.com> wrote:
>
> Seems odd to be asking these questions without asking someone from the
MediaWiki team involved (I doubt they are subscribed to oss-sec).  Given
that Murray just posting what was written by upstream and even asked "if
CVE worthy" I doubt he has the answers you're looking for.  =)
>
> I've cc'd Markus Glaser to this as he sent out the notification to the
mediawiki-announce list so he may have the insight you're looking for.
>
>
> On 02/28/2014, at 11:26 AM, cve-assign@...re.org wrote:
>
> > Some of this seems straightforward and we will send CVE assignments a
> > little later. Our first question is about the UploadBase.php diff in:
> >
> >
https://gerrit.wikimedia.org/r/#/q/7d923a6b53f7fbcb0cbc3a19797d741bf6f440eb,n,z
> >
> > Our first thought is that it might be best to have separate CVEs for
> > "Disallow uploading non-whitelisted namespaces" and "disallow iframe
> > elements" because they are distinct types of problems. The first one
> > seems similar to what is discussed in:
> >
> > http://en.wikipedia.org/wiki/User:Aarchiba/SVG_sanitize of
> >
> > The first CVE would, roughly, have a root cause of "does not recognize
> > that a trust relationship with a specific external site is reasonably
> > required for use of a namespace." The second CVE would, roughly, have
> > a root cause of "does not block IFRAME elements."

With the whitelisted set of namespaces, iirc, iframe doesn't have a valid
definition. It was the combination of the iframe and the namespace that
allowed the js to execute.

> >
> > Does anyone have an opposing view: for example, that adding the
> > hardcoded $validNamespaces list can't be interpreted as a "normal"
> > vulnerability fix? Across all products, adding a list of off-site URLs
> > maintained by various third parties is rarely the essence of a
> > security patch.
> >
> > (As a side issue, SVG_sanitizer allows
> > http://www.w3.org/XML/1998/namespace but the patched UploadBase.php
> > does not.)
> >
> >
> > Our second question is about
> > https://bugzilla.wikimedia.org/show_bug.cgi?id=61346 Comment 9. Do all
> > valid tokens have the same length, and thus an attacker (if he looked
> > at the source code) would already know that the wrong-length attempts
> > would always fail?

Yes, the token length has been defined by a constant in the code
(USER_TOKEN_LENGTH) for as far back as I've traced it (Tim's 2004 commit).

> >
> > If not, a separate CVE would be needed on the basis of different
> > affected versions.
> >
> > (This question is only about MediaWiki as shipped. If a system
> > administrator would need to modify the source code to use a different
> > length, and an attacker could detect that more easily because of
> > 'strlen( $answer ) !== strlen( $test )' tests, that doesn't qualify
> > for a CVE.)
> >
> > - --
> > CVE assignment team, MITRE CVE Numbering Authority
> > M/S M300
> > 202 Burlington Road, Bedford, MA 01730 USA
> > [ PGP key available through http://cve.mitre.org/cve/request_id.html ]
>
>
> --
> Vincent Danen / Red Hat Security Response Team

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.