Way cool ! HTTP Session Hijacking can’t be made simpler than using Firesheep. Couple of days ago, a friend of mine suggested me to login a most popular website and he demonstrated how he took control and accessed my user session in less than a minute. First, I thought he used a network protocol analyser tool such as Wireshark or sniffer to access my session information…but I was a bit surprised to see he used a simple and user friendly Firefox plugin (Firesheep) to steal and access my session information. Believe it or not – in an unsecured network,  Firesheep can easily capture active user session information exchanged with a Website that uses clear-text/unencrypted HTTP communication and session ID cookies irrespective of their underlying Operating System and user’s Browser. Ofcourse sending and receiving clear-text over HTTP has always posed a huge risk and compromising the session cookie allows impersonation….. interestingly majority of us don’t care much till we become a victim  of a data loss !  Even the many popular social network websites still uses clear-text over HTTP.

With my first experience, Firesheep worked well on my Mac… capturing my Facebook and WordPress sessions running on a PC… so quick ! Not just Facebook sessions – if you are using an unsecured/clear network and accessing any unsecured web site (without SSL), Firesheep can act as a “Man-in-the-Middle” attacker who can comfortably capture, hijack and obtain unauthorized access to the currently active user’s HTTP session. Unfortunately, there is no silver bullet to thwart these attacks unless you are aware and avoid the risks of using unsecured networks and clear-text communication.

Thwarting Firesheep !

If you are concerned about Firesheep attacks on the client side (user’s browser) then make sure to use a Secured VPN or Secure Shell (SSH) or IPSec or Encrypted WiFi (ex.WPA2) connection for accessing unsecured web applications. In case of accessing from unsecured networks, you may use Blacksheep tool which helps to find out whether your user session is currently being captured by a rogue Firesheep user on the network. In case of accessing Facebook, you may consider using HTTPS Everywhere a firefox extension that allows to rewrite Facebook requests and other HTTPS supported Websites.

On the server-side, if you are curious about securing your web application and user sessions from prying eyes….here is some best practices that can help thwarting similar session hijacking attacks:

1. Use SSL/TLS communication to ensure encrypted transport between the user’s client and Web server.
2. Use encrypted session cookies and use encrypt/decryption mechanisms for setting and getting of cookie data.
3. Enable Hostname/IP address verification for all critical requests,  identify and compare the current user’s host with the originating user’s host in the user’s session cookie.

If you are concerned about SSL/TLS overheads and looking for high-performance SSL/TLS acceleration solutions then refer to my previous entries..that would able to help you.

Goodluck.