Loadable Kernel Module sets Linux USER stack space as a non executable area. It will prevent normal stack overflow exploitation, this is not a 100% solution for buffer overflows.
Odysseus is a proxy server, which acts as a man-in-the-middle during an HTTP session. A typical HTTP proxy will relay packets to and from a client browser and a web server. Odysseus will intercept an HTTP session's data in either direction and give the user the ability to alter the data before transmission.
Internet Storm Center 2003/1/23
This particular form for XSS uses the common 'TRACE' protocol, which web servers provide for debugging purposes. If the 'TRACE' protocol is used (instead of the usual GET or POST), all data send to the server is echoed back to the client.