Session Hijacking – What is it and How to Prevent it?

Our day barely ends without surfing the internet, when in doubt – we log into different websites or portal to clear our queries. When users log in to the website that requires them to fill in a form, a session is generated. A session refers to the ongoing communication between two systems, which continues until the user terminates it. Initiating a session is crucial for internet-based communication, but it also introduces the potential risk of session hijacking.

You must be wondering what is session hijacking, right? But fret not, as this blog walks you through all the ins and outs of session hijacking in a very clear way. Give it a read to understand session hijacking in a simple and easy way.

What is Session Hijacking?

Session hijacking is a security attack where an unauthorized user obtains access to an authenticated user’s session by enabling them to imitate their identity. This attack involves stealing session tokens or cookies through techniques like packet sniffing or cross-site scripting. To avoid session hijacking, using safe and secured connections like HTTPS, enforcing strong session management, and optimizing techniques like session timeouts and multi-factor authentication (MFA) is necessary.

How does a Session Hijacking Attack Work?

A session hijacking attack occurs when an attacker captures a user's session token or cookie to simulate them. This can happen through methods like packet sniffing on unsecured networks or cross-site scripting (XSS) to steal session data. Once the attacker has the session information, they can access the user’s account and perform unauthorized actions, leading to data breaches or fraud.

Types of Session Hijacking

Let’s learn in detail about different types of session hijacking to mitigate them with a robust security posture.

1. Session Fixation

The attacker sets a session ID to a known value before the user logs in. Once the user authenticates, the attacker uses that same session ID to gain access.

2. Session Sidejacking

The interception of session cookies is done that are transmitted over unsecured networks; a common example is public Wi-Fi. Attackers can use packet sniffing tools to capture these cookies.

3. Cross-Site Scripting

Attackers inject malicious scripts into web pages viewed by users. These scripts can steal session cookies or other confidential details which allows attackers to hijack sessions.

4. Cross-Site Request Forgery (CSRF)

An attacker manipulates users into submitting a request to a web application where they are authenticated. This can lead to unauthorized actions being performed on behalf of the user.

5. Cookie Theft

Attackers misuse vulnerabilities in web applications to steal cookies directly from the user's browser, which can then be used to simulate users’ identity.

Session Hijacking Prevention Tips

Let’s discover the proven tips to prevent session hijacking attacks. Check them out to achieve robust security.

1. Use HTTPS

Always use HTTPS to encrypt data between the user’s browser and your server. This prevents attackers from intercepting session tokens. Implement HSTS to enforce HTTPS connections.

2. Enforce Secured Cookies Policy

Set the "Secure" flag on cookies to ensure they are only sent over HTTPS. Use the "HttpOnly" flag to prevent JavaScript from accessing cookies, which allows you to guard against XSS attacks.

3. Regenerate Session IDs

Regenerate session IDs after a user logs in to prevent session fixation. It’s also a good idea to regularly change session IDs during active sessions, especially after sensitive actions.

4. Set Short Session Timeouts

Implement session timeouts to log users out after periods of inactivity. Limiting the duration of active sessions minimizes the window of opportunity for attackers.

5. Secure Server-Side Management

Store session data securely on the server side and avoid storing confidential details in cookies. Use secure session management practices to minimize vulnerabilities.

Concluding Statement

Session hijacking is a serious problem, and it significantly affects the security of web applications. Hence, this blog covers a simplified concept of session hijacking, how session hijacking works, types of session hijacking, and powerful tips to achieve session hijacking prevention. We hope this blog has helped you understand session hijacking to the core.