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On 2011-01-04T06:09:48+00:00 Tim Starling wrote:

Clickjacking is a type of vulnerability discovered in 2008, which is
similar to CSRF.

The attack involves displaying the target webpage in a iframe embedded
in a malicious website. Using CSS, the submit button of the form on the
target webpage is made invisible, and then overlaid with some button or
link on the malicious website that encourages the user to click on it.
For more information, see:

  http://en.wikipedia.org/wiki/Clickjacking
  http://www.owasp.org/index.php/Clickjacking

Web browsers have standardised on a defence called X-Frame-Options,
which puts the onus on the web application to prevent framing of
sensitive content.

Wikipedia user PleaseStand brought it to our attention that despite the
passage of more than two years, MediaWiki still had no defence against
clickjacking. PleaseStand pointed out that when user or site JavaScript
or CSS is enabled ($wgAllowUserJs, $wgAllowUserCss, $wgUseSiteJs or
$wgUseSiteCss), clickjacking is essentially equivalent to cross-site
scripting (XSS), that is to say, it allows full compromise of the
account of the user visiting the malicious website.

A fix will be shortly released, in MediaWiki 1.16.1. Our approach is to
allow framing of basic page views and search pages, but to deny framing
of special pages unless they have explicitly opted out of clickjacking
protection. By taking this moderate approach, instead of denying all
framing, we hope to avoid having system administrators disable the
security feature by patching it out.

Security-conscious system administrators may wish to disable framing
entirely using $wgBreakFrames = true. In MediaWiki 1.16.1 or later, this
will provide protection against clickjacking vulnerabilities in
extensions which opt out incorrectly or embed sensitive forms on pages
which are opted out.

Alternatively, you can configure your web server to send an X-Frame-
Options header on all pages. For example with Apache mod_headers:

   Header always set X-Frame-Options DENY

For MediaWiki 1.15.x or earlier branches, we will provide a simplified
security patch which denies all framing.

Extensions which wish to allow framing on a given page should do so by
calling $wgOut->allowClickjacking(). This should only be done on pages
which do not contain CSRF-protected forms or links. Any extension which
embeds a CSRF-protected form in an unprotected article view page should
call $wgOut->preventClickjacking(), after Article::view() has called
$wgOut->allowClickjacking(), to reset the flag.

To be protected against clickjacking, all users need to use a browser
which supports the X-Frame-Options header. Our patch does include
standard frame-breaking JavaScript code, but this is known to be
insufficient for most browsers. See the OWASP article for more details.
For information on supported browsers, see:

<https://developer.mozilla.org/en/the_x-frame-options_response_header>

Reply at: https://bugs.launchpad.net/mediawiki/+bug/697451/comments/0

------------------------------------------------------------------------
On 2011-01-04T07:10:36+00:00 Tim Starling wrote:

Fixed in trunk in r79561.

Release announcement:
<http://lists.wikimedia.org/pipermail/mediawiki-announce/2011-January/000093.html>

Simplified patch for 1.15.x:
http://www.mediawiki.org/wiki/Special:Code/MediaWiki/79566

Reply at: https://bugs.launchpad.net/mediawiki/+bug/697451/comments/1


** Changed in: mediawiki
       Status: Unknown => Fix Released

** Changed in: mediawiki
   Importance: Unknown => High

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Title:
  CVE-2011-0003: clickjacking vulnerability in mediawiki <1.16.1

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