Session Management

Session Management is a crucial component of web security, particularly in the context of the OWASP Top 10. It deals with how a web application manages user sessions, including the creation, maintenance, and termination of user sessions.

Session

A session refers to a series of interactions between a user and a web application that occurs within a given time frame.

Session ID

A unique identifier assigned to a user session, typically stored as a cookie or URL parameter.

Session Hijacking

A security attack where a malicious actor takes over a user's session and gains unauthorized access to their account.

Creating a Session

Here's a simple example of creating a session in PHP:

session_start(); // Start the session
$_SESSION['user_id'] = $user_id; // Store user ID in session
                

Validating a Session

To validate a session, check if the session ID exists and is valid:

session_start();
if (!isset($_SESSION['user_id'])) {
    header("Location: login.php"); // Redirect to login if session is invalid
    exit();
}
                

Terminating a Session

To terminate a session, destroy the session data:

session_start();
session_unset(); // Remove all session variables
session_destroy(); // Destroy the session
                

• Use secure, random session identifiers.
• Implement session expiration and inactivity timeouts.
• Use HTTPS to protect session IDs during transmission.
• Regenerate session IDs upon login and privilege escalation.
• Implement logout functionality to allow users to end sessions.