A security issue was identified and fixed in mozilla-thunderbird:

Unspecified vulnerability in Mozilla Firefox 3.5.x through 3.5.14
and 3.6.x through 3.6.11, when JavaScript is enabled, allows remote
attackers to execute arbitrary code via unknown vectors, as exploited
in the wild in October 2010 by the Belmoo malware (CVE-2010-3765).

Packages for 2009.0 are provided as of the Extended Maintenance
Program. Please visit this link to learn more:
http://store.mandriva.com/product_info.php?cPath=149&products_id=490

Additionally, some packages which require so, have been rebuilt and
are being provided as updates.