Session hijacking, also known as session fixation or session theft, is a cyberattack technique where an attacker gains unauthorized access to a user's active session on a computer system or a web application. The objective of session hijacking is to impersonate the victim and take control of their ongoing session, allowing the attacker to perform actions on behalf of the victim without their knowledge or consent. This type of attack can have serious consequences, including identity theft, unauthorized access to sensitive information, or the ability to perform malicious actions on a victim's behalf.
Session Hijacking Methods :
Stealing : In this technique, attackers intercept or steal session identifiers or tokens from their intended victims. This can be achieved through various means, including packet sniffing, cross-site scripting (XSS) attacks, or by accessing session data stored on the user's device.
Guessing : Attackers attempt to guess valid session identifiers through various methods, such as using common or predictable values, calculate . This is often based on the assumption that weak session token generation practices are in place.
Brut – Forcing : Brut Forcing is process of guessing every possible combination of credential. Attackers often use brute force attacks to guess usernames and passwords, which can then be used to gain access to a user's session.
Session hijacking Process :
Sniffing : Attackers use packet sniffing tools to intercept and capture network traffic between the victim's device and the server. It uses sniffing to capture sensitive information, including session identifiers or authentication credentials, from the intercepted packets.
Monitoring : It monitor the network traffic, attackers monitor and analyze the captured data to identify valuable session-related information. It uses monitoring to identify and extract session tokens or credentials from the captured traffic.
Session Desynchronization : Attackers may attempt to desynchronize the session state between the victim and the server. This can involve manipulating data or session parameters and disrupt the connection of session. It uses to create confusion or instability in the session, potentially allowing the attacker to take control.
Session ID : Attackers use the session identifier or token they've obtained to impersonate the victim's session. It uses session id gain unauthorized access to the victim's session and perform actions on their behalf.
Command Injection : Attackers may inject malicious commands or requests into the captured traffic, which, when executed by the server, can have unintended consequences or provide the attacker with unauthorized access. After successful taking over session, attacker starts injecting commands to get unauthorized transactions or data manipulation.
Types of Attacks :
Active Attack : An active attack involves an attacker directly interacting with the target system or network to compromise security. In the context of session hijacking, this means the attacker actively takes steps to intercept, manipulate, or control the session or the communication between the user and the server. Example : Intercepting and altering network traffic between a user and a server by performing a man-in-the-middle (MitM) attack. Injecting malicious packets into the network to disrupt or hijack a session.
Passive Attack : Passive attack, on the other hand, involves an attacker monitoring and observing network traffic or sessions without actively modifying or interacting with them. The attacker collects information passively and may not be immediately detected. Example : Packet sniffing to capture network traffic and collect data, such as session tokens or credentials, without altering the data. Eavesdropping on unencrypted communication to gain information without actively interfering.
Session Hijacking Techniques :
Session Sniffing :
Session sniffing is a network security attack in which an attacker intercepts and captures data packets. This technique allows the attacker to eavesdrop on network communications, potentially capturing sensitive information, including usernames, passwords, session tokens, or other data. The attacker uses a packet-sniffing tool or software to capture data packets from the network. Once the attacker captures the data packets, they analyze the packet contents to identify information of interest. This could include HTTP requests, emails, file transfers. The attacker looks for specific types of sensitive data within the captured packets, such as login credentials, session tokens, or other confidential information. It's important to note that session sniffing is typically a passive attack, meaning the attacker observes the network traffic without actively sending packets or altering the data. This makes it difficult to detect.
Man-in-the-Middle Attack :
A Man-in-the-Middle (MitM) attack is a common method used in session hijacking to intercept and manipulate communication between two parties, such as a user and a server, without their knowledge or consent. The attacker positions themselves between the victim and the target server, allowing them to eavesdrop on, modify, or redirect the communication. The attacker positions themselves in a location where they can intercept the traffic passing between the user (victim) and the target server. This can be done on a local network. Then attacker typically impersonates the target server or service to make the user believe they are communicating directly with the legitimate entity. As the attacker intercepts data packets passing between the user and the server, they capture sensitive information, such as session identifiers, login credentials, or any data being transmitted. The attacker may choose to modify the intercepted traffic. For example, they can inject malicious scripts or code into web pages, altering the content the user sees or the data they submit. Alternatively, they can redirect the user to a fake login page to steal their credentials.
Cross-Site Script Attack :
A Cross-Site Scripting (XSS) attack is a client-side security vulnerability that can be used as part of a session hijacking attack. XSS attacks occur when an attacker injects malicious scripts (typically JavaScript) into web pages or web applications. The attacker identifies a vulnerable input field or parameter within a web application, such as a search bar, comment form, or user profile. The attacker inserts malicious JavaScript code as input into the vulnerable field. This code is stored on the server, making it accessible to anyone who views the page. When a legitimate user visits the web page containing the injected script, their browser loads and executes the malicious JavaScript code. The malicious script can access and steal session cookies or other session-related data stored in the user's browser.
Brut-Force Attack :
A brute force attack is a trial-and-error method used by attackers to guess a secret, such as a password or session identifier, by systematically attempting all possible combinations until the correct one is found. The attacker identifies the target session or user account they want to compromise. This could be a session identifier, a username, or both. The attacker generates a list of possible session identifiers or passwords, depending on the target. For session identifiers, they may generate random combinations or try known patterns. They repeatedly send requests to the target server, each time using a different guessed value. The attacker checks the server's response to each attempt to determine if the guess was correct. If they receive a successful login response or access to the session, they have successfully guessed the correct value. With the correct session identifier or login credentials, the attacker can now gain unauthorized access to the victim's session or account. They can impersonate the user and perform actions on their behalf.
Session Fixation :
In a session fixation attack, the attacker sets or fixes a user's session identifier or token before the user logs in or authenticates themselves. Once the victim logs in, the attacker can use the predetermined session identifier to impersonate the user and gain unauthorized access to their session. The attacker identifies a web application or system that uses session identifiers or tokens for user authentication and session management. Then attacker acquires a valid session identifier or token. The attacker fixes or sets the acquired session identifier as the victim's session token. This can be done by setting a cookie in the victim's browser, modifying the session state on the server, or manipulating URL parameters. The attacker tricks the victim into visiting the target web application or system and logging in without changing the session identifier. When the victim logs in, they are assigned the session identifier that the attacker set. The attacker, who also knows this session identifier, can now use it to impersonate the victim's session and gain unauthorized access.
Conclusion :
In conclusion, session hijacking is a serious security threat that can have severe consequences for individuals and organizations. There are a number of things that can be done to prevent session hijacking, such as using strong passwords, enabling two-factor authentication, Use a VPN , keeping your software up to date, and avoiding public Wi-Fi networks when possible. If you think that you may have been the victim of session hijacking, there are a few things you can do, such as changing your passwords immediately, contacting the website or service that was compromised, and reporting the attack to the authorities. Overall, session hijacking is a persistent and evolving threat in the world of cybersecurity. Staying informed about the latest attack techniques and best practices for prevention and mitigation is crucial to safeguarding sensitive data and ensuring the security and privacy of users and organizations in an increasingly interconnected digital landscape.
