The remote host is missing an update to iceweasel announced via advisory DSA 2341-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202341-1

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-2011-3647 moz_bug_r_a4 discovered a privilege escalation vulnerability in addon handling. CVE-2011-3648 Yosuke Hasegawa discovered that incorrect handling of Shift-JIS encodings could lead to cross-site scripting. CVE-2011-3650 Marc Schoenefeld discovered that profiling the Javascript code could lead to memory corruption. For the oldstable distribution (lenny), this problem has been fixed in version 1.9.0.19-15 of the xulrunner source package. For the stable distribution (squeeze), this problem has been fixed in version 3.5.16-11. For the unstable distribution (sid), this problem has been fixed in version 8.0-1. We recommend that you upgrade your iceweasel packages.