When people connect online to transfer or exchange information, it is generally termed as a communication session. Hijacking is defined as an activity of unlawfully taking control of something in a way that causes inconvenience to the valid or rightful users. Hijacking can be of anything like a bus, aircraft, rail, computer systems, etc. Let’s explore more about session hijacking in this post.
What is Session Hijacking?
Session hijacking is also a type of hijacking where attackers hack an ongoing session between two systems or networks. It is an attack carried out by hackers to compromise the security of two or more networks on which a communication session is taking place. It is carried out to steal information between valid and authorized users to abuse them or compromise the network security for personal gains. Hackers can not only impersonate themselves as valid users but also can gain access to sensitive data on the network(s). This leads to data breaches.
Session hijacking technique uses cookies to take control over a computer session so it is also called cookie hijacking. Generally, hackers steal the magic cookie (or HTTP cookie) which is used to authenticate the user and connect with a remote server. When any hacker gets access to the session through this technique, they have access to all the resources which are available to use for valid users.
Purpose of Session Hijacking attacks
The main purpose of this hijacking attack is to gain access to the information shared in that session and the information stored on the victim’s system. It can be very challenging for users to communicate online without having any encryption as these types of attacks are mainly successful in unencrypted sessions where the communication session is carried out without encryption. Therefore, security is a primary requirement for having a good communication session where the information is secure among the valid and authorized users and no unauthorized user (hacker) can enter it in disguise.
Session hacking is possible at two levels: Application-level & Network-level. Network-level session hijacking involves TCP and UDP sessions & Application-level session hijacking involves HTTP sessions. Hackers use some important information gained as a result of attacks carried out at Network levels to attack sessions at Application levels, so they are carried out together. Network level hijacking is most commonly used by attackers to steal information as it is easier to carry out because they do not have to customize the attacks as per web applications. They only attack the data flow of the protocol which is usually the same for all applications.
Types of Session Hijacking attacks
Session hijacking attacks can be broadly classified into Active hijacking & Passive hijacking.
- Active hijacking: Hackers take place of the user in this type of attack and carry out the communication exchange between the system and the server. The valid user is made incapable of being a part of the session so that the attacker can easily take control of the session on behalf of the user. The attacker can exchange information between the server and his/her system and access the data stored on the server, thereby, the attacker can create new user accounts, delete existing user accounts and command like the original user. This is more dangerous than Passive attack as it can harm more. The intention of the hacker here is to manipulate the information available on the server which makes this attack more harmful than passive attacks.
- Passive hijacking: In this type of hijacking, hackers do not actively manipulate the data on the server but they monitor the flow of information secretly without letting their existence to be known to others. They steal useful information such as user ids, passwords, etc by monitoring the network traffic. It is also called as session sniffing as the attacker is not doing anything except monitoring. The main purpose of this attack is to get sensitive information shared on the network session. It is less dangerous than active hijacking because hackers have limited rights.
Threats associated with Session Hijacking
Some of the threats related to session hijacking attacks are
- Attackers impersonate valid users and gain control over the network.
- Hackers can manipulate the data stored at the victim’s machine and the server.
- Sensitive data is exposed to attackers.
- Important functions like creating new users, deleting users, and commanding functions can be used by hackers.
- Authorized users lose their access to the session or have limited access due to this attack.
Prevention of Session Hijacking attacks
As discussed above, session hijacking is a serious threat so it is necessary to prevent it by implementing measures which are essential to keep the exchange of information safe and safeguard the security of both networks.
Some preventive measures are listed below which can help to prevent the session hijacking to a great extent.
- Network-level hijacking can be avoided by implementing ciphering packets in which information is stored in a way that hackers cannot decipher them. The ciphering can be done by using some protocols like SSL, SSH, IPSec, etc. Internet security protocol (IPSec) can encrypt the packets of information on some shared key between two intended users who are communicating. IPSec operates in two modes; Transport mode & Tunnel mode. Transport mode offers encryption to only to data sent in the packet but Tunnel mode offers encryption to both data sent and headers in the packet.
- Application-level hijacking can be prevented by using only Strong Session ID’s. It can prevent the network from being hijacked at any cost as hackers cannot decrypt it easily. SSL & SSH protocols also offer great security to the network.
- After a successful login, the session id can be regenerated to avoid the session being hijacked.
- Logging out when users do not use the session to carry out an exchange of information or some task.
Note: If this post helped you gain some useful information, please like and share it with others.
Howdy! This blog post couldn’t be written much better! Looking through this post reminds me of my previous roommate! He always kept preaching about this. I most certainly will forward this information to him. Pretty sure he’ll have a good read. Thank you for sharing!