[MediaWiki-announce] MediaWiki security release 1.16.4

Tim Starling tstarling at wikimedia.org
Thu Apr 14 07:47:18 UTC 2011

Our patch for the Internet Explorer 6 XSS issue (bug 28235) released
two days ago in 1.16.3 was insufficient to fix that bug. The original
reporter, Masato Kinugawa, pointed out the flaw on bug 28507. So we
are doing another release, which contains a second attempt at fixing
the issue.

Apologies to everyone for the inconvenience. Big thanks go to Masato
Kinugawa for helping to keep MediaWiki secure. Thanks also to Roan
Kattouw who helped me test the patch this time around, so that we can
hopefully avoid a repeat.

It is necessary to upgrade MediaWiki to avoid an XSS vulnerability for
Internet Explorer clients, version 6 and earlier. Also, if you used
the Apache configuration I suggested in the previous release
announcement, you should update it to:

    RewriteEngine On
    RewriteCond %{QUERY_STRING} \.[a-z0-9]{1,4}(#|\?|$) [nocase]
    RewriteRule . - [forbidden]

We missed the fact that there can be more than one question mark in a
URL. In certain circumstances, IE 6 will use a file extension
immediately before a question mark character, regardless of how many
question marks precede it. For example, with the URL:


IE 6 will see the file extension as ".html".


Patch to previous version (1.16.3):

GPG signatures:

Public keys:

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