How does regenerating session IDs after login prevent session fixation and hijacking? Learn why this security measure is critical for blocking attackers from forcing predictable session IDs—essential for CompTIA Security+ (Plus) SY0-701 exam success.
Table of Contents
Question
An attacker forces a user to log in using a predefined session ID, allowing session hijacking. Which security measure prevents this?
A. Regenerating session IDs after login
B. Increasing password complexity
C. Enforcing rate limiting
D. Encrypting session cookies
E. Using TLS
Answer
A. Regenerating session IDs after login
Explanation
Prevents attackers from forcing a predictable session ID on victims.
The security measure that prevents attackers from forcing a user to log in with a predefined session ID (enabling session hijacking) is regenerating session IDs after login.
In a session fixation attack, an attacker sets or predicts a session ID and tricks a user into authenticating with it. If the application continues to use the same session ID after login, the attacker can hijack the session.
The most effective defense is to regenerate a new session ID immediately after successful authentication. This ensures that any session ID known or set by the attacker before login becomes invalid once the user is authenticated.
By issuing a fresh, unpredictable session ID post-login, the application ensures only the legitimate user receives the valid session, blocking the attacker from accessing the authenticated session—even if they previously controlled the session ID.
This practice is recommended by security experts and is supported by most modern web frameworks as a core defense against session fixation and related hijacking techniques.
Additional best practices include using secure, random session IDs, setting appropriate cookie attributes (HttpOnly, Secure), and enforcing HTTPS for all session traffic.
Regenerating session IDs after authentication prevents attackers from exploiting predefined or predictable session IDs, effectively blocking session fixation and hijacking attempts.
CompTIA Security+ (Plus) SY0-701 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the CompTIA Security+ (Plus) SY0-701 exam and earn CompTIA Security+ (Plus) SY0-701 certification.