Firesheep

Firesheep was an extension for the Firefox web browser that used a packet sniffer to intercept unencrypted session cookies from websites such as Facebook and Twitter. The plugin eavesdropped on Wi-Fi communications, listening for session cookies. When it detected a session cookie, the tool used this cookie to obtain the identity belonging to that session. The collected identities (victims) are displayed in a side bar in Firefox. By clicking on a victim's name, the victim's session is taken over by the attacker.^[2]

The extension was released October 2010 as a demonstration of the security risk of session hijacking vulnerabilities to users of web sites that only encrypt the login process and not the cookie(s) created during the login process.^[3] It has been warned that the use of the extension to capture login details without permission would violate wiretapping laws and/or computer security laws in some countries. Despite the security threat surrounding Firesheep, representatives for Mozilla Add-ons stated initially that it would not use the browser's internal add-on blacklist to disable use of Firesheep, as the blacklist has only been used to disable spyware or add-ons which inadvertently create security vulnerabilities, as opposed to attack tools (which may legitimately be used to test the security of one's own systems).^[4] Since then, Firesheep has been removed from the Firefox addon store.

A similar tool called Faceniff was released for Android mobile phones.^[5]

• Session hijacking
• Cookie hijacking
• HTTPS
• Transport Layer Security
• HTTP Strict Transport Security

• Firesheep home page
• Eric Butler
• New York Times article about Firesheep