Natas Level 3 to 4 Write Up

Here’s my write up for Natas level 3! I’ll be publishing write ups as I traverse through the challenges. These write ups are meant to display my thought process behind solving the challenges. At the end I add what security best practices to implement to avoid these vulnerabilities in real life! Enjoy!

Log into http://natas3.natas.labs.overthewire.org/

Again, I view the rendered HTML and I find the hint. It says “No more information leaks!! Not even google will find it this time!” My first thought is that the hint is referring to web crawlers. Google uses web crawlers to find pages and index the internet. If Google is, in theory, not supposed to find the password, there must be a robots.txt file in use.

Robots.txt is a file that is meant to tell web crawlers which pages they can and cannot crawl. It can be used as a map of the website. Some web crawlers will obey whatever is listed here and some won’t

So I add robots.txt to the end of the URL and I see there’s one directory that is disallowed.

I navigate to this directory and I can again view the files located here. One being users.txt. I now have the password for Natas level 4!

Security best practice takeaway: For URLs that are truly meant to be private and not publicly accessible, utilize IP address whitelisting or password protection.

Thanks for reading! I’m a Security Engineer who’s goal it is to share what I learn- and if it helps others that’s a bonus. If you’d like to connect with me, check out my LinkedIn.