Sidejacking, a technique of hijacking web sessions of other users in the network, has suddenly gained much attention on the Internet, thanks to a new Firefox extension Firesheep.

In a sidejacking session, the attacker sniffs data packets of the transactions over the network and steals cookie which the attacker can then use to impersonate the victim on the site the user is currently logged in. Even if they have encrypted login pages, unsecured HTTP sites use cookies to identify you during the entire session and this is what the attacker exploits. An attacker with certain tools can steal the cookie during transaction and use it to make the server treat the hijacker as the legitimate user. This vulnerability has existed since a long time but exploiting it was never so easy nor was it as alarming. Continue reading Sidejacking: How to prevent Firesheep from hijacking your session →