The remote host is missing an update to mozilla-thunderbird announced via advisory DSA 1134-1. Several security related problems have been discovered in Mozilla which are also present in Mozilla Thunderbird. For details, please visit the referenced security advisories.

For the stable distribution (sarge) these problems have been fixed in version 1.0.2-2.sarge1.0.8a. For the unstable distribution (sid) these problems have been fixed in version 1.5.0.4-1 and xulrunner 1.5.0.4-1 for galeon and epiphany. We recommend that you upgrade your Mozilla Thunderbird packages. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201134-1