The remote host is missing an update to drupal6 announced via advisory DSA 1808-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201808-1

Markus Petrux discovered a cross-site scripting vulnerability in the taxonomy module of drupal6, a fully-featured content management framework. It is also possible that certain browsers using the UTF-7 encoding are vulnerable to a different cross-site scripting vulnerability. For the stable distribution (lenny), these problems have been fixed in version 6.6-3lenny2. The oldstable distribution (etch) does not contain drupal6. For the testing distribution (squeeze) and the unstable distribution (sid), these problems have been fixed in version 6.11-1.1. We recommend that you upgrade your drupal6 packages.