Cookie Tossing

👉 Overview

👀 What ?

Cookie tossing is a security exploit that manipulates the way cookies are handled in a domain and its subdomains, enabling an attacker to hijack a user's session and gain unauthorized access to their accounts.

🧐 Why ?

This topic is important because it exposes the vulnerabilities in the way browsers handle cookies. If exploited, it can lead to serious privacy and security breaches, such as unauthorized access to sensitive information and potential data loss. Understanding how cookie tossing works is vital for both users and developers to take appropriate preventative measures.

⛏️ How ?

To leverage cookie tossing, an attacker would typically set a cookie in a subdomain, and the browser would mistakenly send this cookie to the main domain. This allows the attacker to hijack the user's session. To protect against this, users should regularly clear their cookies and developers should implement secure coding practices, such as validating all cookies and setting the Secure and HttpOnly flags.

⏳ When ?

The practice of cookie tossing began to be widely recognized as a serious security issue around the mid-2000s, as e-commerce and online banking started to grow and the need for secure online transactions became more apparent.

⚙️ Technical Explanations

In a cookie tossing attack, the attacker exploits the fact that browsers do not isolate cookies from different subdomains. They create a cookie on a subdomain they control (e.g., evil.example.com) with the same name as a cookie used on the main domain (example.com). When the user visits the main domain, the browser sends both cookies. Since the server expects only one cookie with that name, it may use the wrong one, allowing the attacker to hijack the user's session. This attack relies on the server not properly validating the cookies, and can be mitigated by implementing secure cookie management practices.