Web Security Project
Prerequisites
For this project, you are going to use a virtual machine running (an ancient) version of Linux. We provide basic VM images for both Oracle VirtualBox and VMware. CSL Linux machines all have VirtualBox pre-installed.
VMware is only available free on Linux and Windows; if you have VMware fusion for Mac that may work as well.
Environment Setup
Highly Recommended Environment Setup: VNC Server and Client
To enable functionality such as copying and pasting from your host machine and being able to gracefully resize your window, we
strongly
recommend that you use a VNC client to interact with the virtual machine.
- Install a VNC client on your host machine. Any client should work; we recommend the open-sourceUltraVNCLinks to an external site.
.
- Make sure that your virtual machine has the following port forwarding option:
Name |
Protocol |
Host IP |
Host Port |
Guest IP |
Guest Port |
VNC |
TCP |
127.0.0.1 |
8888 |
|
5901 |
Refer to homework 1 if you want to know how to set up a port forwarding option.
- After logging into the virtual machine, run the command
vncserver :1to start the server. The:1makes sure that the server is listening on the correct port, so don't change it.
- The first time you run this, the program will ask you to set a password for the server. You can run
vncpasswdif you ever need to change it.
- Mac Users: Safari has a built in VNC client. To use Safari to connect to the VNC, go to
vnc://127.0.0.1:8888
- Open your VNC client. Instruct the client to connect to 127.0.0.1:8888. However, be aware that using it may cause some crashing/freezing. A dedicated piece of VNC software is recommended.
- Input the password you set for the VNC server and you should see the screen.
Now that you have connected to the virtual machine using VNC, you can use thexclipcommand to copy and paste things from your host machine to the virtual machine. To copy the text of a file in the virtual machine, runxclip filename.
To set the size of your VNC window, add the parametervncserver :1 -geometry 1920x1080, replacing 1920x1080 with whatever resolution you prefer.
How to run Iceweasel
The Web server serving the Zoobar site you will be attacking is hosted inside the VM. (If you try to connect to zoobar.org outside the VM, you will get Stanford's site, which you should not try to interact with.) Furthermore, the Web browser you'll use to develop and test your attacks is also hosted inside the VM. It is called Iceweasel.
Iceweasel is the Debian version of Firefox (essentially the same browser, but with a different name because of licensing issues). To start Iceweasel in BoxesX, login as user, and do the following:
- If you are not using VNC, type thestartxcommand. This will start the X Window System, and a new window will be displayed with a xterm (shell) where you can enter commands. (Click the mouse to place the window.)
- Typeiceweasel &within the xterm. This will open the Iceweasel browser. (Again, click the mouse to place the window.)
- In the URL bar, you can type
http://zoobar.org/(Links to an external site.)
Project Overview
The fictional “Zoobar Foundation” has set up a simple Web application at zoobar.org (inside the BoxesX VM), allowing registered users to post profiles and transfer “zoobar” credits between each other. Each registered user starts with 10 "zoobar" credits.
You will craft a series of attacks on zoobar.org that exploit vulnerabilities in the website design. Each attack presents a distinct scenario with unique goals and constraints, although in some cases you may be able to reuse parts of your code.
Although many real-world attackers do not have the source code for the websites they are attacking, you are one of the lucky ones: you can find the source code under
/var/zoobar/www
in the BoxesX VM.
The Zoobar server is actually run locally on each of your boxes. We will run your attacks after wiping clean our own local database of registered users (except the user named “attacker”). Of course this means that any data you have added while working on the assignment will not be present during grading.
Before Start
Browser:We will grade your project within the BoxesX VM, using the Iceweasel browser, which is installed in the Boxes. Therefore, you should test your code in the boxes on this browser. Iceweasel is essentially the same browser as Firefox, but under different branding. Anything that works in iceweasel will likely work in (the same version of) Firefox as well. There are subtle quirks in the way HTML and JavaScript are handled by different browsers, and some attacks that work in Internet Explorer (for example) may not work in Firefox (and therefore in Iceweasel). In particular, you should use the Mozilla way of adding listeners to events (see
https://developer.mozilla.org/en/DOM/element.addEventListener(Links to an external site.)
Email script:For Attack A, you will need a server-side script to automatically email information captured by your client-side JavaScript to your user account within the Boxes. We have provided this script for you. Please review the instructions at
http://zoomail.org/sendmail.php(Links to an external site.)
mutt
in the shell to start the client, and follow the instructions).
Attack A: Cookie Theft (30 pts)
- Your solution is a URL starting with
http://zoobar.org/users.php(Links to an external site.)
?
- The grader will already be logged into zoobar.org before loading your URL.
- Your goal is to steal the document cookie and email it to yourself using the email script.
- When sending the email with the stolen document cookie, the group name of the email has to be set to your net ID.
- Except for the browser address bar (which can be different), the grader should see a page that looks exactly as it normally does when the grader visits users.php. No changes to the site appearance or extraneous text should be visible. Avoiding the red warning text is an important part of this attack. (Its ok if the page looks weird briefly before correcting itself.)
- Note: You need to log into Zoobar before you execute your attack. Otherwise the cookie will not exist and your attack will appear to do nothing.
- Hint: Here is an example attack to use as a starting point:
http://zoobar.org/users.php?user=\%22\%3E\%3Cscript\%3Ealert\%28document.cookie\%29;\%3C/script\%3E
Attack B: Cross-Site Request Forgery (40 pts)
- Your solution is a short HTML document that the grader will open using the browser.
- The grader will already be logged into zoobar.org before loading your page.
- Transfer 10 zoobar credits from the grader's account to the account named "attacker".If your code transfers credits to an account that is not named "attacker", you may lose points!This account is not registered in the VM image we provide, you will have to register the "attacker" account yourself. The browser should be redirected to
http://www.bing.com
(Links to an external site.)
as soon as the transfer is complete (so fast the user might not notice).
- The location bar of the browser should not contain
zoobar.orgat any point.
Attack C: SQL Injection (30 pts)
- Your solution is a short HTML document that the grader will open using the browser.
- The grader will not be logged into zoobar.org before loading your page.
- Your HTML document should display a form with a text field and a button. The grader will type a username into the text field and press the button.
- As a result, the grader should be logged into zoobar.org as the user whose name was typed in the text field. The browser's location bar should be redirected to
http://zoobar.org/index.php(Links to an external site.)
- The name the grader types in will already be registered with some password. You do not need to handle the case in which the name was not already registered.
- Hint: What part of the zoobar.org PHP code handles the user login and registration, and how does it interface with the SQLite database?
- Your attack must be successful if runmultiple times. Attacks that are only successful once will receive 15/20 points for the implementation component.
Tips
- If you need to transfer files from your main machine to your virtual machine, there is a command to use:
scp -r -P 8024 [email protected]:. Note you cannot edit/var/www. Alternatively, if you are using VNC, you can usexclipas described above.
- The zoobar source files are here:HW2-zoobar.zip
HW2-zoomail.zip
Collaboration Policy
This assignment is to be done in your assigned group. You are encouraged to use the internet or talk to classmates for information about tools and setup. Please help your fellow classmates with setup and understanding HTML , JavaScript or SQL, but don't discuss solution specifics with anyone. Remember, searching for homework solutions online isacademic misconduct. If two groups' submissions are very similar --- for some definition of similarity --- both students will get zero points for this assignment.
Deliverables
- Submit the 3 files
a.txt, b.html, c.htmlcorresponding to 3 attacks respectively.
- For each attack, describe (1) the vulnerability you exploited (2) how/why your attack works and (3) one idea for how to mitigate the vulnerability. Put your answers in a file called
solutions.txt.
Grading
If the attack works, one will receive full credit. Partial credit will be given for a good description of the vulnerability and how an exploit should work.