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Cookie Poisoning

Explore the risks and prevention of cookie poisoning with Keepnet Labs. Learn how it impacts web security and best practices to safeguard against it. Perfect for IT professionals and cybersecurity researchers Hackers using this attack method can modify or create new cookie values. Cookie manipulation often results in unauthorized access to user accounts or sensitive data.

Cookie Poisoning

Cookie poisoning is a hacking method. Session hijacking is a term used to describe cookie poisoning. This term is used because these attacks often focus on compromising session cookies.

Hackers using this attack method can modify or create new cookie values. Cookie manipulation often results in unauthorized access to user accounts or sensitive data.

What is Cookie Poisoning?

Cookie poisoning is a hacking method where hackers alter or forge website cookies. This malicious activity enables unauthorized access to sensitive information. In a cookie poisoning example, hackers can impersonate users, leading to information theft. This hacking technique particularly exploits vulnerabilities in web applications, making it a significant concern for cyber security.

Cookie Poisoning Example .jpeg
Picture 1: Cookie Poisoning Example

How do cookies work

Cookies are small pieces of data that websites send to your browser. They help websites remember information about your visit. Think of them as little memory aids for websites.

Is it risky to accept cookies?

Accepting cookies on websites is only sometimes risky, but it's good to be careful. Here's why:

  • Privacy: Cookies remember what you do online. They help websites know your likes. But they can tell others about what you do online, too.
  • Safety: Usually, cookies are safe. But, if you visit a good website, it might use cookies correctly. They could let hackers see your online steps.
  • Ads: Have you ever noticed advertisements that understand your preferences? That's because of cookies. They tell advertisers what interests you.
  • Choice: Good news! You can say yes or no to cookies. Websites in places like Europe must ask you first.
  • Easy Web Surfing: Cookies can make browsing easier. They remember your logins and what you like on websites.

Cookie poisoning attack example

In the section on cookie poisoning attack examples, we will explore specific scenarios where attackers manipulate the data stored in cookies to exploit online systems. This cookie poisoning attack example illustrates how seemingly harmless cookie data, such as shopping cart details and pricing information, can be altered to benefit the attacker.

This manipulation leads to unauthorized advantages, like reduced prices or unauthorized access, demonstrating the critical need for secure cookie-handling practices. By understanding this example, users and developers can better recognize and prevent vulnerabilities within their web environments.

''GET /shop/checkout.php?checkout=yes HTTP/1.0


Accept: /


Cookie: SESSIONID=AH153HJF8986KNL; BasketSize=2; Item1=19; Item2=30; Item3=42; TotalPrice=164;''

In this case, the browser asks for a page called "checkout.php." It tells the Web server that the user wants to complete a purchase by using the "checkout=yes" part. The request also includes a cookie.

This cookie has details like "SESSIONID" (a unique code linking the user to the site), "BasketSize" (the number of items being bought), the price of each item, and the "TotalPrice." When the web server gets this request, checkout.php looks at the cookie, checks the details, and processes the payment based on the "TotalPrice." An attacker might change the "TotalPrice" in the cookie to pay less than the actual price.

What is client dom cookie poisoning?

Client DOM Cookie Poisoning is a popular web cyber attack. It involves tampering with the cookies in a web browser.

Imagine a hacker altering these cookies. They inject harmful data into them. This type of cookie stealing often uses JavaScript, a common language for creating and managing websites.

How to prevent cookie poisoning

To protect yourself from cookie poisoning, where a hacker changes a website's cookies on your computer. You need to know about cookie poisoning prevention. This means taking steps to keep your cookies safe. Here are some easy ways:

  • Use Secure Browsers: Pick browsers known for good security features. They can better manage and protect cookies.
  • Update Regularly: Keep your browser and security software current. Updates often include fixes for security problems.
  • Be Careful Online: Only visit trusted websites. Avoid clicking on suspicious links. Phishing awareness reduces the risk of encountering harmful cookies.
  • Clear Cookies: Regularly delete your cookies. Cookie cleaning limits the time a poisoned cookie could be on your computer.
  • Check Settings: Adjust your browser settings to increase security. You can block third-party cookies or choose to approve cookies each time a website wants to store one.
  • Use Private Browsing: When using public or shared computers, use private browsing modes. When you close the browser, the system deletes cookies.
  • VPN for Extra Security: VPN encrypts your network traffic. Additional encryption on your traffic secures your account, especially when using public Wi-Fi.
  • Be Wary of Public Wi-Fi: Avoid accessing sensitive accounts, like banking, on public Wi-Fi. These networks are more vulnerable to attacks.

Check out the video to learn more about cookie poisoning and prevention.

Keepnet Labs Solution

Keepnet Awareness Educator offers cookie poisoning and session hijacking training for your employee's cybersecurity awareness.

Use our phishing simulator to identify vulnerabilities like cookie poisoning, session hijacking, and session replay attacks. It can help you simulate phishing attacks and test your security measures.

You can use our Phishing Simulator with Evilginx2 man-in-the-middle attack vector to understand:

  • Does your web application prevent cookie poisoning?
  • Does cookie poisoning work for your employee's account?
  • Can session hijacking prevention methods work for your application?

See how you can use Evilginx2 with the Phishing Simulator below.

Please also look at our Phishing Simulator from the video below and see how to simulate attacks to test your security against cookie poisoning attacks.



Schedule your 30-minute private demo now.

You will learn:
tickHow to conduct a cookie poisoning in a phishing simulation.
tickHow to train your employees about cookie security awareness.
tickHow to prevent session hijacking in your organization.

Frequently Asked Questions

What Constitutes Cookie Poisoning and Its Impact on Web Security?

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Cookie poisoning is the manipulating or forgery of a website's cookies to access sensitive data unauthorizedly. This method underlines the necessity for stringent cybersecurity defenses due to its potential to facilitate data breaches and exploit web application vulnerabilities.

How Do Website Cookies Function, and What Is Their Safety for Users?

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Websites use Cookies as small data fragments to retain information about a user's visit, aiding in personalized web experiences. While cookies are predominantly safe, their acceptance can sometimes raise privacy and security concerns depending on the security measures of the visited website.

Could You Provide an Instance of a Cookie Poisoning Attack?

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An attack instance may involve altering cookie content, such as modifying shopping cart details or pricing, to unlawfully manipulate online systems, leading to unauthorized privileges or access, showcasing the critical need for secure cookie management practices.

What Is Meant by Client DOM Cookie Poisoning in Cybersecurity?

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This cyber attack targets manipulating web browser cookies via malicious data injection, often employing JavaScript. It represents a significant threat to users privacy and security, emphasizing the importance of vigilant web usage and security practices.

What Measures Can Individuals Take to Safeguard Against Cookie Poisoning?

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Protecting against cookie poisoning involves adopting secure web browsing habits, ensuring regular updates of software, exercising caution on the internet, periodically clearing cookies, tweaking browser security settings for enhanced protection, utilizing private browsing modes on communal devices, and leveraging VPN services for encrypted online activity, particularly on unsecured public networks.

Is it risky to accept cookies?

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  • Privacy Concerns: Cookies can track browsing activities for targeted ads, potentially compromising privacy.
  • Security Risks: Accepting cookies from suspicious sites can expose you to attacks like session hijacking.
  • Data Storage: Cookies use storage space on your device, which can accumulate over time.
  • Consent and Control: You can usually accept or decline cookies, with settings to manage them for better security.
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