The remote host is missing an update to fckeditor announced via advisory DSA 2522-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202522-1

Emilio Pinna discovered a cross site scripting vulnerability in the spellchecker.php page of FCKeditor, a popular html/text editor for the web. For the stable distribution (squeeze), this problem has been fixed in version 1:2.6.6-1squeeze1. For the testing distribution (wheezy), this problem has been fixed in version 1:2.6.6-3. For the unstable distribution (sid), this problem has been fixed in version 1:2.6.6-3. We recommend that you upgrade your fckeditor packages.