The remote host is missing an update to iceweasel announced via advisory DSA 1555-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201555-1

It was discovered that crashes in the Javascript engine of Iceweasel, an unbranded version of the Firefox browser could potentially lead to the execution of arbitrary code. For the stable distribution (etch), this problem has been fixed in version 2.0.0.14-0etch1 For the unstable distribution (sid), this problem has been fixed in version 2.0.0.14-1. We recommend that you upgrade your iceweasel package.