mediawiki - several vulnerabilities

Several vulnerabilities have been discovered in mediawiki, a web-based wiki
engine. The following issues have been identified:

• Insufficient input sanitization in the CSS validation code allows editors
  to display external images in wiki pages. This can be a privacy concern
  on public wikis as it allows attackers to gather IP addresses and other
  information by linking these images to a web server under their control.
• Insufficient permission checks have been found in thump.php which can lead
  to disclosure of image files that are restricted to certain users
  (e.g. with img_auth.php).

For the stable distribution (lenny), these problems have been fixed in
version 1.12.0-2lenny4.

For the testing distribution (squeeze), these problems have been fixed in
version 1:1.15.2-1.

For the unstable distribution (sid), these problems have been fixed in
version 1:1.15.2-1.