Session Management Lifecycle

Session Lifecycle Overview

Session Lifecycle: The lifecycle of a session typically involves the following stages:

• Session Creation: The initial phase where a session is established.
• Session Assign: Assigning session identifiers (IDs) to users.
• Session Exchange: Handling how sessions are used and maintained.
• Session Termination: Properly ending the session to prevent unauthorized access.

1. Session Creation

• Session ID Strength: Ensure the session ID is long, random, and has high entropy to avoid brute-force attacks or predictability.
• Cookie Set with Parent Domain: Cookies should be tied to a specific subdomain if needed. Setting them to a parent domain (e.g., example.com instead of login.example.com) could allow access to other subdomains and increase risk.
• Cookie Path Attribute Set Insecurely: The Path attribute in cookies should limit the scope of the cookie. Misconfiguring it can expose the session to parts of the site where it's not needed.
• Session Puzzling Attack: This occurs when session management is broken across multiple domains or services, allowing attackers to mix and match session pieces to escalate privileges or hijack sessions.

2. Session Assign

• Cookie Created Without the HttpOnly Flag: Cookies should always have the HttpOnly flag to prevent client-side scripts (JavaScript) from accessing the cookie, protecting against XSS attacks.
• Cookie Created Without the Secure Flag (SSL): The Secure flag ensures the cookie is only sent over HTTPS, preventing attackers from intercepting session cookies over unencrypted connections.

3. Session Exchange

• Session ID Contained in URL: Storing session IDs in URLs exposes them through browser history, logs, or referrer headers. Always store session IDs in cookies, not URLs.
• Multiple Sessions Allowed: Allowing a single user to log in from multiple devices simultaneously without managing or limiting sessions can lead to session hijacking risks. Consider session invalidation upon new logins, if necessary.
• IP Hopping: A user’s IP address changes during a session (due to proxies, VPNs, etc.), and the system doesn’t validate session integrity, leading to potential session theft. While this is tricky, binding a session to an IP (or requiring some form of validation) helps.
• Kiosk Issue: In shared environments (like kiosks or public computers), failing to properly terminate sessions after use allows subsequent users to hijack the session. Implementing timeouts and “remember me” features that are disabled in such cases helps mitigate this.

4. Session Termination

• No Logout Button: The absence of a logout option means users cannot actively terminate their session. Always provide a logout feature to give users control over session termination.
• Session Expiration Issue: Sessions should automatically expire after a set period of inactivity. Without this, sessions remain active indefinitely, which can lead to unauthorized access.
• Session Not Expired on Logout: Ensure that session cookies and tokens are properly invalidated on the server side upon logout. Otherwise, attackers can reuse the old session.
• Session Timeout: A short idle timeout helps limit the impact of stolen or forgotten sessions. Idle sessions should expire after a reasonable amount of inactivity.