This topic, and Firefox add-on have received a lot of press lately, as such I figured that I’d capture some comments on the topic. HTTP Session hijacking is nothing new, anyone with the ability to monitor your non-secured network traffic can do this with little effort… what’s happened here is that there are now some really simple to use tools to do the job.
In the past, someone would have to passively monitor your network traffic with a tool like WireShark, and all they’d really have to do is wait for you to access a website to watch the ‘HTTP Cookies’ (or even a URL that contains a ‘session id’). With that information, they simply need to use the same value that you do to essentially take over your session and your current state. Banks are particularly at risk for this, but in most cases they use HTTPS/SSL for all secure data including logins. Social websites such as Facebook and even GMail, often default to non-secure logins to maximize their server and network performance.
Best defense here… never use non-secure login forms, especially when using a public wireless (or wired) network.
Interesting enough, there’s now a Firefox add-on that monitors for usage of Firesheep on the network, unfortunately neither of these currently work in Linux… links below!