The remote host is missing an update to mozilla-thunderbird announced via advisory DSA 1051-1. For details on the issues addressed by the missing update, please visit the referenced security advisories.

For the stable distribution (sarge) these problems have been fixed in version 1.0.2-2.sarge1.0.8. For the unstable distribution (sid) these problems have been fixed in version 1.5.0.2-1 of thunderbird. We recommend that you upgrade your Mozilla Thunderbird packages. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201051-1