mediawiki - security update

It was reported that MediaWiki, a website engine for collaborative work,
allowed to load user-created CSS on pages where user-created JavaScript
is not allowed. A wiki user could be tricked into performing actions by
manipulating the interface from CSS, or JavaScript code being executed
from CSS, on security-wise sensitive pages like Special:Preferences and
Special:UserLogin. This update removes the separation of CSS and
JavaScript module allowance.

For the stable distribution (wheezy), this problem has been fixed in
version 1:1.19.20+dfsg-0+deb7u1.

For the unstable distribution (sid), this problem has been fixed in
version 1:1.19.20+dfsg-1.

We recommend that you upgrade your mediawiki packages.