Seeking help with known exploits of the following technologies.....

$$ Windows

$$ Hypervisor $($Cintrix$$s XenServer$)$

$$ Apache $2.$X

$$ PHP

$1.$ Three known vulnerabilities or exploits.

$2.$ Best way to mitigate these vulnerabilities.

$3.$ Software$/$hardware components that can be used to protect a website.

$4.$ Best way to monitor web server for ongoing security alerting.