The remote host is missing an update to iceweasel announced via advisory DSA 2514-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202514-1

Several vulnerabilities have been discovered in Iceweasel, a web browser based on Firefox. The included XULRunner library provides rendering services for several other applications included in Debian. CVE-2012-1948 Benoit Jacob, Jesse Ruderman, Christian Holler, and Bill McCloskey identified several memory safety problems that may lead to the execution of arbitrary code. CVE-2012-1950 Mario Gomes and Code Audit Labs discovered that it is possible to force iceweasel to display the URL of the previous entered site through drag and drop actions to the address bar. This can be abused to perform phishing attacks. CVE-2012-1954 Abhishek Arya discovered a use-after-free problem in nsDocument::AdoptNode that may lead to the execution of arbitrary code. CVE-2012-1966 moz_bug_r_a4 discovered that it is possible to perform cross-site scripting attacks through the context menu when using data: URLs. CVE-2012-1967 moz_bug_r_a4 discovered that in certain cases, javascript: URLs can be executed so that scripts can escape the JavaScript sandbox and run with elevated privileges. Note: We'd like to advise users of Iceweasel's 3.5 branch in Debian stable to consider to upgrade to the Iceweasel 10.0 ESR (Extended Support Release) which is now available in Debian Backports. Although Debian will continue to support Iceweasel 3.5 in stable with security updates, this can only be done on a best effort base as upstream provides no such support anymore. On top of that, the 10.0 branch adds proactive security features to the browser. For the stable distribution (squeeze), this problem has been fixed in version 3.5.16-17. For the unstable distribution (sid), this problem has been fixed in version 10.0.6esr-1. We recommend that you upgrade your iceweasel packages.