The remote host is missing an update to xulrunner announced via advisory DSA 1425-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201425-1

Several remote vulnerabilities have been discovered in Xulrunner, a runtime environment for XUL applications. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2007-5947 Jesse Ruderman and Petko D. Petkov discovered that the URI handler for JAR archives allows cross-site scripting. CVE-2007-5959 Several crashes in the layout engine were discovered, which might allow the execution of arbitrary code. CVE-2007-5960 Gregory Fleischer discovered a race condition in the handling of the window.location property, which might lead to cross-site request forgery. The oldstable distribution (sarge) doesn't contain xulrunner. For the stable distribution (etch) these problems have been fixed in version 1.8.0.14~pre071019c-0etch1. For the unstable distribution (sid) these problems have been fixed in version 1.8.1.11-1. We recommend that you upgrade your xulrunner packages.