The remote host is missing an update to xulrunner announced via advisory DSA 1669-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201669-1

Several remote vulnerabilities have been discovered in Xulrunner, a runtime environment for XUL applications. For details on the issues addressed with this update, please visit the referenced security advisories. For the stable distribution (etch), these problems have been fixed in version 1.8.0.15~pre080614h-0etch1. Packages for mips will be provided later. For the upcoming stable distribution (lenny) and the unstable distribution (sid), these problems have been fixed in version 1.9.0.4-1. We recommend that you upgrade your xulrunner packages.