Bypassing CloudFlare Error 1015: You Are Being Rate Limited

Welcome back to my new article! I’m Mohammed Nafeed, a bug bounty hunter.

Bug hunting is an exciting and challenging field that involves finding and reporting vulnerabilities in software, websites, and applications.

What is Rate Limit Attack?

Answer: A rate limit attack is when an attacker floods a system with a high volume of requests to exhaust its resources or cause it to slow down, making it unavailable for legitimate users.

For example sending of unlimited verification code to any user globally leads to spam their inbox.

Let’s dive into my recent experience with website testing. I was conducting tests on a particular website and decided to try a rate limit attack. To my surprise, the attack was successful, allowing me to send over 1000+ Gmail verification codes to any user. However, as soon as I exceeded 100 requests, Cloudflare’s security measures kicked in, displaying an “Error 1015: You Are Being Rate Limited.”

This Cloudflare blockage prevented me from taking any further actions on the website. At this point, I was faced with a challenge. Being blocked by Cloudflare’s firewall security was a roadblock, but with my bug hunting experience, I decided to think outside the box. I started to experiment with the URL, testing for case sensitivity vulnerabilities.

I tried manipulating the URL by changing the case of certain letters, such as converting uppercase (A) to lowercase (a). This approach was based on the idea that some web servers and firewalls might treat URLs differently based on case sensitivity. To my surprise, this tactic worked, and I was able to bypass the rate limit restriction.

Normal URL:

https://www.example.com/web/Participant/profile/ChangePassword.aspx

Bypassed URL:

https://www.example.com/web/Participant/profile/changepassword.aspx

What is Case Sensitive Vulnerability?

A case-sensitive vulnerability occurs when an application or system does not treat uppercase and lowercase characters as distinct. This can lead to security issues because an attacker can manipulate the input case to bypass authentication, access unauthorized data, or perform other malicious activities. For example, if a system checks passwords in a case-insensitive manner, an attacker could enter a password with different cases to gain unauthorized access. Proper handling of case sensitivity is essential to ensure the security and integrity of applications and systems.

This experience highlighted the importance of thorough testing and thinking creatively when it comes to bug hunting. It’s not always about finding a direct vulnerability; sometimes, it’s about understanding how different components interact and finding unconventional ways to exploit or bypass security measures.

In the world of bug bounty hunting, every challenge presents an opportunity to learn and improve. This incident served as a reminder of the importance of persistence, creativity, and continuous learning in the field of cybersecurity.

So, the next time when you see an error or a rate limit message on a website, try switching things up a bit. You never know what you might find!

Proof of Concept:

https://drive.google.com/file/d/1OlGHZKCpp3ehH0dKYqJVqn7AvXOUCVkr/view?usp=drivesdk

If the above video link doesn’t work kindly message me in Instagram.

Thank You….

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