Happy Monday! I spent the better part of this weekend thinking about denial of service, but rather than releasing a tool, I thought it would be worthwhile to talk about how denial of service attacks could be used in tandem with other attacks to exploit other logical or business issues. Let’s take a few examples:
Timing: Let’s say you have a site that accepts bids up to a certain time of day - say an auction site or a site that allows you to bid on work or whatever. Most of the time people submit their bids as close to the deadline as they can so that their competitors don’t have time to revise their bids. Sure, you can write a robot to come in at the last fraction of a microsecond and underbid, but what if you want to keep your bid highest or lowest (depending on the type of site)? Well by submitting your bid earliest and then denying service to the application for the remainder of the time your competitors don’t have a chance to submit their bids.
Web services: Sometimes, it’s not a matter of denying service to the site itself, which may have all sorts of robust protections in place, but sometimes the web service is actually more interesting. This could include things like authentication or even email. Let’s say I know someone is traveling and they use their phone to get their email. If I know they are in charge of responding to events, I can deny service to the webmail server and poof - suddenly they are no longer getting updates that something else is going on that they need to take care of.
Diversionary: And that leads us to the last item on the list which is using denial of service as a diversionary tactic. Sure, we can just do the bad thing that we intend to, but wouldn’t it be so much better to throw a red herring in there to cause them to look in the wrong place while the attacker stealthily gets whatever he wants elsewhere?
Anyway, it’s an interesting concept to talk about. I think most people think of DoS as a simple script kiddy menace without considering it’s other useful purposes. And now, with a case of the Mondays, it’s time to buckle down for a lonnng week.