What is Session Hijacking?

Session hijacking occurs when a session token is sent to a client browser from the Web server following the successful authentication of a client logon. A session hijacking attack works when it compromises the token by either confiscating or guessing what an authentic token session will be, thus acquiring unauthorized access to the Web server. This can result in session sniffing, man-in-the-middle or man-in-the-browser attacks, Trojans, or even implementation of malicious JavaScript codes.

Web developers are especially wary of session hijacking because the HTTP cookies that are used to sustain a website session can be bootlegged by an attacker.