The remote host has a web browser installed that is vulnerable to multiple attack vectors.
Versions of Mozilla Firefox 1.5.x prior to 18.104.22.168 are affected by a flaw that could lead to a Denial of Service (DoS) condition within the browser. In addition, the version of Firefox is reported vulnerable to a buffer overflow when processing malformed XML documents. An attacker exploiting either of these flaws would need to be able to convince a user to visit a malicious URI.
Upgrade to version 22.214.171.124 or higher.