Another day, another challenge.
This post we will solve challenge 7 of the OWASP Hackademic Challenge.
Below is the scenario:
A good friend of mine studies at Acme University, in the Computer Science and Telecomms Department. Unfortunately, her grades are not that good. You are now thinking “This is big news!”… Hmmm, maybe not. What is big news, however, is this: The network administrator asked for 3,000 euros to change her marks into A’s. This is obviously a case of administrative authority abuse. Hence… a good chance for D-phase and public exposure…
I need to get into the site as admin and upload an index.htm file in the web-root directory, that will present all required evidence for the University’s latest “re-marking” practices!
I only need you to find the admin password for me…
Clicking on the link we see the following:
Right clicking on the page we see the following:
We see that there is a folder named index_files. Let’s go this folder and see what’s there…
Well look what we have here… there’s a lastlogin.txt, clicking on that file we get the following:
We see that Irene is a valid user. Let’s go back to the beginning and add Irene to the text box (with TamperData on) and see what we get.
Let’s press “OK”, and continue.
Reloading the page we now see the following in TamperData:
Well what do we have here? Inside the cookie we have the user of Irene and a userlevel of “user”. Lets try to change the userlevel to admin and see if this will solve our challenge.
After pressing out we get the following screen:
Page source provided gems in this challenge. When doing the page source we noticed that there was a folder “index_files”. When accessing this folder we see that there was information that was disclosed incorrectly that showed the last login of the application. This is bad because another user (in this case us) can impersonate a valid user.
Once we checked the grade for our user of “Irene” and looked at the tamper data results we noticed there was a cookie header that showed that our user had a privilege level of user. We noticed that this value can be changed. After change the privilege from user to admin we completed the challenge successfully.
When creating an application make sure that information is not being disclosed improperly. Make sure that there are no open folders that can be accessed on the website.