The remote host is missing an update to fetchmail announced via advisory USN-816-1.

The problem can be corrected by upgrading your system to the following package versions: Ubuntu 6.06 LTS: fetchmail 6.3.2-2ubuntu2.3 Ubuntu 8.04 LTS: fetchmail 6.3.8-10ubuntu1.1 Ubuntu 8.10: fetchmail 6.3.8-11ubuntu3.1 Ubuntu 9.04: fetchmail 6.3.9~rc2-4ubuntu1.1 In general, a standard system upgrade is sufficient to effect the necessary changes. https://secure1.securityspace.com/smysecure/catid.html?in=USN-816-1

Moxie Marlinspike discovered that fetchmail did not properly handle certificates with NULL characters in the certificate name. A remote attacker could exploit this to perform a man in the middle attack to view sensitive information or alter encrypted communications.