Computer security Question:

Server side includes, snippets of server directives embedded in HTML documents, are another potential hole. A subset of the directives available in server-side includes instruct the server to execute arbitrary system commands and CGI scripts. Unless the author is aware of the potential problems it's easy to introduce unintentional side effects. Unfortunately, HTML files containing dangerous server-side includes are seductively easy to write.

Some servers, including Apache and NCSA, allow the Web master to selectively disable the types of includes that can execute arbitrary commands.