The remote host is missing an update to postgresql-8.4 announced via advisory USN-876-1.
Details follow:
It was discovered that PostgreSQL did not properly handle certificates with NULL characters in the Common Name field of X.509 certificates. An attacker could exploit this to perform a man in the middle attack to view sensitive information or alter encrypted communications. (CVE-2009-4034)
It was discovered that PostgreSQL did not properly manage session-local state. A remote authenticated user could exploit this to escalate priviliges within PostgreSQL. (CVE-2009-4136)
Solution: The problem can be corrected by upgrading your system to the following package versions: