To answer this question, we need to understand what a session-hijacking attack is and what information is essential for a hacker to perform such an attack.
Session hijacking, also known as session sidejacking, is a type of attack where an attacker gains unauthorized access to a user's session by stealing or impersonating their session identifier. This allows the attacker to take control of the user's session and perform actions on their behalf.
Let's go through each option to understand why it is correct or incorrect:
Option A) Session ID - This option is incorrect. The session ID is indeed an important piece of information for a session-hijacking attack, as it helps the attacker impersonate the user's session. However, it is not the essential information required for this attack.
Option B) Session number - This option is incorrect. While a session number might be used in some systems to identify a user's session, it is not a widely recognized or essential piece of information for session hijacking.
Option C) Sequence number - This option is correct. The sequence number is a crucial piece of information for a hacker performing a session-hijacking attack. The sequence number is used to maintain the order of packets exchanged between the client and the server during a session. By obtaining and manipulating the sequence number, an attacker can inject malicious packets into the session and disrupt the communication between the client and the server.
Option D) Source IP address - This option is incorrect. While the source IP address can provide some information about the origin of the session, it is not an essential piece of information for a session-hijacking attack. The focus of session hijacking is on stealing or impersonating the session identifier, rather than the source IP address.
Therefore, the correct answer is option C) Sequence number. This option is correct because the sequence number is essential for a hacker to perform a session-hijacking attack by injecting malicious packets into the session.