The remote host is missing an update to jabberd14 announced via advisory DSA 2249-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202249-1

Wouter Coekaerts discovered that jabberd14, an instant messaging server using the Jabber/XMPP protocol, is vulnerable to the so-called billion laughs attack because it does not prevent entity expansion on received data. This allows an attacker to perform denial of service attacks against the service by sending specially crafted XML data to it. The oldstable distribution (lenny), does not contain jabberd14. For the stable distribution (squeeze), this problem has been fixed in version 1.6.1.1-5+squeeze1. For the testing distribution (wheezy), this problem will be fixed soon. For the unstable distribution (sid), this problem has been fixed in version 1.6.1.1-5.1 We recommend that you upgrade your jabberd14 packages.