What should I be afraid of when I make a site public?

Question

If I was going to put my site for the public's use, what are some security issues that I should be worried about?

I know of SQL injections. What other hacks/injections should I be aware of?

Answer 1

Cross-site scripting

Cross-site request forgery

Answer 2

It depends heavily on what kind of site you're putting up. Sites that deal with commerce and payment systems need to be more secure then a site detailing how to wash your cat.

In essence the more personal user interaction a site has, the more it's going to need to be checked for security vulnerabilities. A static html site will probably not have many issues while a site that allows people to register, purchase items, pay with a credit card online, etc, is going to need a much closer look at things under the hood.

Answer 3

If you accept credit cards, you're probably incurring at least a 15 cent cost per transaction, success or fail. You'll want to make sure that malicious people can't continually hit your payment confirmation page. Not just for the 15 cents a hit, but after you've submitted enough bad transactions, your provider will likely want to have a chat with you.