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

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>

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

This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected Fedora
versions.

For comments that are specific to the vulnerability please use bugs filed
against "Security Response" product referenced in the "Blocks" field.

For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs

When creating a Bodhi update request, please include the bug IDs of the
respective parent bugs filed against the "Security Response" product.
Please mention CVE ids in the RPM changelog when available.

Bodhi update submission link:
https://admin.fedoraproject.org/updates/new/?type_=security&bugs=667199

Please note: this issue affects multiple supported versions of Fedora.
Only one tracking bug has been filed; please only close it when all
affected versions are fixed.

[bug automatically created by: add-tracking-bugs]

mediawiki-1.16.2-56.fc14 has been submitted as an update for Fedora 14.
https://admin.fedoraproject.org/updates/mediawiki-1.16.2-56.fc14

mediawiki-1.16.2-56.fc13 has been submitted as an update for Fedora 13.
https://admin.fedoraproject.org/updates/mediawiki-1.16.2-56.fc13

mediawiki-1.16.2-56.fc15 has been submitted as an update for Fedora 15.
https://admin.fedoraproject.org/updates/mediawiki-1.16.2-56.fc15

mediawiki-1.16.4-57.fc14 has been submitted as an update for Fedora 14.
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-57.fc14

mediawiki-1.16.4-57.fc13 has been submitted as an update for Fedora 13.
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-57.fc13

mediawiki-1.16.4-57.fc15 has been submitted as an update for Fedora 15.
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-57.fc15

Package mediawiki-1.16.4-57.fc14:
* should fix your issue,
* was pushed to the Fedora 14 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing mediawiki-1.16.4-57.fc14'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-57.fc14
then log in and leave karma (feedback).

mediawiki-1.16.4-57.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report.

mediawiki-1.16.4-58.fc14 has been submitted as an update for Fedora 14.
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-58.fc14

mediawiki-1.16.4-58.fc13 has been submitted as an update for Fedora 13.
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-58.fc13

mediawiki-1.16.4-58.fc15 has been submitted as an update for Fedora 15.
https://admin.fedoraproject.org/updates/mediawiki-1.16.4-58.fc15

mediawiki-1.16.4-58.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report.

mediawiki-1.16.4-58.fc14 has been pushed to the Fedora 14 stable repository. If problems still persist, please make note of it in this bug report.

mediawiki-1.16.4-58.fc13 has been pushed to the Fedora 13 stable repository. If problems still persist, please make note of it in this bug report.