which patches and hotfixes were applied to my CF server?

It's even worse then JR indicated.

There are several Hot Fixes that did not use Jar files.  They where just modifications to various configuration XML files.  The only way to know if those have been implimented is to look at the relevant configuration file.

Unfortunately CF does not make this easy.  You will need to login to the CF administrator site and go to the System Information page.  One of the items listed is the "Update Level" which will list the latest hotfix you have applied.  For other fixes look at the files listed in the "Java Class Path" section of the Systems Information page.  Hotfix files are generally named hf*.jar where * starts with the CF version number you are running.  You can check the available hotfixes to verify that you have the ones you need.

You should also verify that you are running the latest supported JVM:

http://kb2.adobe.com/cps/894/cpsid_89440.html

CF 9 hotfixes:
http://kb2.adobe.com/cps/529/cpsid_52967.html

CF 8 hotfixes:
http://kb2.adobe.com/cps/402/kb402604.html