Session Hijacking Definition

KZero Staff
Oct 18, 2023

Session hijacking, also known as session fixation or session theft, is a cyberattack in which an attacker gains unauthorized control over a user’s active session. This attack can lead to the unauthorized access of sensitive data, fraudulent transactions, and various other security breaches.

How do these attacks happen?

Session hijacking typically occurs when an attacker intercepts or steals the session identifier (session ID) or session cookie of a legitimate user.

A session ID is a unique token generated by a web application for each user’s session. It is often stored as a cookie or URL parameter and is used to identify and authenticate the user. Session hijacking attacks can be carried out through various means, including network eavesdropping, cross-site scripting (XSS) vulnerabilities, and session fixation.

Impact & Prevention

Once an attacker gains control over a user’s session, they can impersonate the legitimate user, perform actions on their behalf, access their sensitive data, or manipulate the session to execute malicious actions.

To prevent session hijacking, organizations implement secure session management practices, employ encryption, and frequently rotate session IDs. Additionally, strong authentication and access controls help thwart these attacks.


Session hijacking is a critical concern in web applications and online services. Attackers seek to exploit vulnerabilities or weak session management to gain unauthorized access to user accounts and sensitive data. By implementing robust security measures, organizations can effectively mitigate the risks associated with session hijacking and protect their users’ privacy and data.

KZero Staff

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