We recently published an advisory for PartyPoker, an online gambling site (SECOBJADV-2008-03.) It was for a weakness in the client update process, a class of vulnerability that can affect various kinds of software. The past few years have seen some vulnerabilities that are specific to online gaming software. Statically seeded random number generators that allow prediction of forthcoming cards and reel values on upcoming slot spins were researched in the early days of online gaming–let’s take a look at some additional threats.
Usually, forms of online cheating are pretty primitive. Justin Bonomo was exposed for using multiple accounts in a single tournament on PokerStars and of course collusion between multiple players occurs as well. Absolute Poker’s reputation took a pretty big hit when players discovered that a site owner used a backdoor to view cards in play. Many private and public bots are also in use. However, a good human poker player will beat a bot, especially in no-limit which is less mathematical than other variations of the game; bots are likely to be most useful in low-stakes fixed-limit games.
Earlier this year, a logic flaw was exploited on BetFair (oh, the pun!) because of a missing conditional check to test for chip stack equality when determining finishing positions. As a result, if multiple players with the same amount of chips were eliminated at the same time, they would all receive the payout for the highest position, instead of decrementing positions. For example, if there were three players that all had chip stacks of the same size and everyone went all-in, the winner of the hand would finish in first place and the other two players would both receive second place money. Interesting!