Session Hijacking, and How to Detect and Prevent It with Practicals

Introduction

Session hijacking is a type of cyberattack that involves taking control of a user’s active session with a web application or service.

A session is created when a user logs into a web application or service, and it remains active until the user logs out or the session expires.

During this time, the user’s browser and the web application exchange information, including session IDs, which are used to identify the user and maintain the session.

An attacker can hijack a session by stealing the session ID, which can be used to impersonate the user and gain access to their account.

Once the attacker has control of the session, they can perform malicious actions on behalf of the user, such as stealing sensitive information, manipulating data, or even taking over the user’s computer.

Session hijacking attacks can take several forms, including man-in-the-middle attacks, session fixation attacks, cross-site scripting (XSS) attacks, and cross-site request forgery (CSRF) attacks.

Each of these attacks exploits different vulnerabilities in the web application or the user’s browser to steal the session ID and gain control of the session.

Preventing session hijacking attacks requires a multi-layered approach that includes both technical and non-technical measures.

By implementing these measures, organizations can help protect their users’ sensitive information and prevent malicious actors from gaining access to their systems and applications.

How does Session Hijacking Work?

Session hijacking is a technique that allows an attacker to take control of a user’s session on a web application, which enables them to access sensitive information or perform actions on behalf of the user. The attack is usually carried out by stealing the user’s session ID, which is a unique identifier that the server uses to keep track of the user’s session.

Session hijacking attacks work by taking advantage of vulnerabilities in the way web applications handle user sessions. When a user logs in to a web application, the application creates a session ID, which is a unique identifier that is used to track the user’s session. The session ID is usually stored in a cookie or as a URL parameter.

During a session hijacking attack, the attacker intercepts the communication between the user and the web application and obtains the session ID. The attacker can then use this session ID to impersonate the user and gain access to their data or resources.

There are several ways that an attacker can obtain the session ID. One of the most common methods is by intercepting network traffic. The attacker can use a network sniffer or a packet analyzer to intercept the communication between the user and the web application. Once the attacker has intercepted the communication, they can extract the session ID from the network traffic.

Another method that an attacker can use to obtain the session ID is by exploiting vulnerabilities in the web application. For example, the attacker can use a SQL injection attack to extract the session ID from the web application’s database.

Once a session has been taken over by a hacker, they can essentially do anything the genuine user was allowed to do while the session was active.

The most serious instances include withdrawing cash from the user’s bank account, making purchases from online shops, obtaining personally identifying information for the purpose of identity theft, and even stealing information from corporate networks.

Types of Session Hijacking

Session hijacking attacks can be classified into several categories based on the techniques used by the attacker. Some of the most common types of session hijacking attacks are:

Man-in-the-Middle (MITM) Attack:

This is the most common type of session hijacking attack. In this type of attack, the attacker intercepts the communication between the user and the web application, and as a result, can obtain sensitive information or execute malicious actions on behalf of the user.

The attacker can perform this type of attack by intercepting network traffic, eavesdropping on the communication between the user and the web application, or using a compromised proxy server.

Session Fixation Attack:

In this type of attack, the attacker forces the user to use a pre-determined session ID, which has already been hijacked by the attacker. The attacker then uses this session ID to gain unauthorized access to the user’s data or resources.

The attacker can perform this type of attack by sending a specially crafted link to the user, which contains the pre-determined session ID.

Cross-Site Scripting (XSS) Attack:

In this type of attack, the attacker injects malicious code into a web page that the user is visiting. The injected code can then steal the user’s session ID, which can be used by the attacker to gain unauthorized access to the user’s data or resources.

Cross-Site Request Forgery (CSRF) Attack:

In this type of attack, the attacker forces the user to perform an action on a web application without their knowledge or consent. The attacker can perform this type of attack by crafting a malicious link that automatically performs an action when the user clicks on it.

For example, the attacker can force the user to transfer funds from their bank account to the attacker’s account.

Session Sniffing:

One of the fundamental methods for application-layer session hijacking is this Session Sniffing.

The network communication between a website and a client is captured by the attacker using a sniffer tool like Wireshark or a proxy like OWASP Zed. Once this value has been obtained, a hacker can use it to access the system without authorization.

Predictable Session ID:

To create session IDs, many web servers utilize either a unique algorithm or a pre-established pattern.

A session token is weaker and more easily predicted the more predictable it is.

An attacker may be able to guess a valid session ID by capturing many IDs and examining their patterns.

Prevention

Session hijacking is a type of attack where an attacker steals the session ID of a legitimate user and uses it to gain unauthorized access to their account. Here are some steps you can take to prevent session hijacking:

Use HTTPS:

HTTPS encrypts data in transit, making it difficult for attackers to intercept and steal session IDs.

Use strong session IDs:

Session IDs should be long, random, and unpredictable. Avoid using sequential numbers or other easily guessable values.

Regenerate session IDs:

Regenerate session IDs periodically or after certain actions, such as logging in or changing a password. This makes it more difficult for attackers to use a stolen session ID.

Store session data securely:

Store session data on the server side and use secure cookies to store session IDs on the client side.

Use two-factor authentication:

Two-factor authentication adds an additional layer of security to the login process, making it more difficult for attackers to hijack a session.

Educate users:

Educate users about the risks of session hijacking and how to recognize and avoid phishing attacks, which are often used to steal session IDs.

By following these steps, you can help prevent session hijacking and protect your users’ accounts.

FAQ

Related Articles on Computer Networks

1. Introduction to Computer Networking | What is Computer Network
2. What are Topology & Types of Topology in Computer Network
3. What is FootPrinting in Cyber Security and its Types, Purpose
4. Introduction to Cloud Computing | What is Cloud Computing
5. Distributed Shared Memory and its advantages and Disadvantages
6. What is VPN? How doe VPN Work? What VPN should I use?
7. What is an Internet and How the Internet Works
8. What is a Website and How Does a Website or web work?
9. Introduction to Virus and different types of Viruses in Computer
10. What is TCP and its Types and What is TCP three-way Handshake
11. What is UDP Protocol? How does it work and what are its advantages?
12. What is an IP and its Functions, What is IPv4 and IPv6 Address
13. What is MAC Address and its Types and Difference MAC vs IP
14. What is ARP and its Types? How Does it Work and ARP Format
15. Sessions and Cookies and the Difference Between Them
16. What is ICMP Protocol and its Message Format?

Recent Articles on Python

1. Continue and Break Statement in Python
2. Definition of Strings in Python with its Examples
3. Numbers in Python | Introduction to Numbers in Python
4. Loop in Python | Different Types of Loop in Python
5. Sets in Python | Python Sets and Operations performs on them
6. Conditional Statements in Python (With Examples)
7. File Handling in Python and Operations performed on File Handling
8. What are Dictionary in Python | Dictionary in Python, advantages
9. Variables and Typecasting in Python || Variables in Python