The remote host is missing an update to nagios2 announced via advisory USN-698-3.
Details follow:
It was discovered that Nagios was vulnerable to a Cross-site request forgery (CSRF) vulnerability. If an authenticated nagios user were tricked into clicking a link on a specially crafted web page, an attacker could trigger commands to be processed by Nagios and execute arbitrary programs. This update alters Nagios behaviour by disabling submission of CMD_CHANGE commands. (CVE-2008-5028)
It was discovered that Nagios did not properly parse commands submitted using the web interface. An authenticated user could use a custom form or a browser addon to bypass security restrictions and submit unauthorized commands. (CVE-2008-5027)
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 8.04 LTS: nagios2 2.11-1ubuntu1.4
After a standard system upgrade you need to restart Nagios to effect the necessary changes.