The remote host is missing an update to horde3 announced via advisory DSA 1966-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201966-1

Several vulnerabilities have been found in horde3, the horde web application framework. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2009-3237 It has been discovered that horde3 is prone to cross-site scripting attacks via crafted number preferences or inline MIME text parts when using text/plain as MIME type. For lenny this issue was already fixed, but as an additional security precaution, the display of inline text was disabled in the configuration file. CVE-2009-3701 It has been discovered that the horde3 administration interface is prone to cross-site scripting attacks due to the use of the PHP_SELF variable. This issue can only be exploited by authenticated administrators. CVE-2009-4363 It has been discovered that horde3 is prone to several cross-site scripting attacks via crafted data:text/html values in HTML messages. For the stable distribution (lenny), these problems have been fixed in version 3.2.2+debian0-2+lenny2. For the oldstable distribution (etch), these problems have been fixed in version 3.1.3-4etch7. For the testing distribution (squeeze) and the unstable distribution (sid), these problems have been fixed in version 3.3.6+debian0-1. We recommend that you upgrade your horde3 packages.