The remote host is missing an update to horde3 announced via advisory DSA 1406-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201406-1

Several remote vulnerabilities have been discovered in the Horde web application framework. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2006-3548 Moritz Naumann discovered that Horde allows remote attackers to inject arbitrary web script or HTML in the context of a logged in user (cross site scripting). This vulnerability applies to oldstable (sarge) only. CVE-2006-3549 Moritz Naumann discovered that Horde does not properly restrict its image proxy, allowing remote attackers to use the server as a proxy. This vulnerability applies to oldstable (sarge) only. CVE-2006-4256 Marc Ruef discovered that Horde allows remote attackers to include web pages from other sites, which could be useful for phishing attacks. This vulnerability applies to oldstable (sarge) only. CVE-2007-1473 Moritz Naumann discovered that Horde allows remote attackers to inject arbitrary web script or HTML in the context of a logged in user (cross site scripting). This vulnerability applies to both stable (etch) and oldstable (sarge). CVE-2007-1474 iDefense discovered that the cleanup cron script in Horde allows local users to delete arbitrary files. This vulnerability applies to oldstable (sarge) only. For the old stable distribution (sarge) these problems have been fixed in version 3.0.4-4sarge6. For the stable distribution (etch) these problems have been fixed in version 3.1.3-4etch1. For the unstable distribution (sid) these problems have been fixed in version 3.1.4-1. We recommend that you upgrade your horde3 package.