This assignment has two parts. It is due by 3/7 at 11:59 PM. To submit your homework, please follow the guidelines on the front page to edit the README in the /writeup folder and push your completed work to GitHub.
Some information you might find helpful for this assignment can be found here.
There will be a late penalty of 5% off per day late!
Elizabeth Moffet has set up a remote server for performing DNS lookups, to make sure people can always access her new banking website at the modern and sophisticated URL: http://1337bank.money. She's pretty sure this service is secure, since all it does is run a Linux DiG command- there's nothing nefarious about performing a DNS lookup!
Apparently, Elizabeth's service is vulnerable, however, to command injection. Can you find the vulnerability? There might be a flag in it for you!
$ nc 1337bank.money 1337
For full credit, write up (step-by-step) how you got the flag and what Elizabeth should do to protect from this vulnerability.
You will earn full credit for answering these questions:
* The right flag
* Showing what input you used to obtain the flag.
* Describing your thought process.
* Any suggested precautions v0idcache could implement to prevent this vulnerability?
Using the provided stub code, implement an interactive shell that leverages the above vulnerability.
You want to be able to conduct the following actions (by calling their respective commands) in this shell:
shellDrop into an interactive shell and allow users to gracefullyexitpull <remote-path> <local-path>Download fileshelpShows this help menuquitQuit the shell
If any malformed input occurs, be sure to show this usage function.
Note: If you choose to write your own program in another language, please include instructions on how to execute your program including what version of the language you are using. Please add this detail to a README.txt or README.md file. You will NOT receive credit if the TAs cannot run your program.
Note: If you are stuck on this part of the assignment, please let us know. The facilitator staff is open to releasing hints, though we reserve the right to deny releasing specific hints if we deem it appropriate.
Note: Here's a screenshot of what we roughly expect. I'll post a simple "public test" for which you will be graded on. Kindly bear with us here, we're trying something new :)
Both parts should be written in the same post, clearly separated. Full, grammatical sentences should be used. Part 1 should be at least 300 words, and part 2 should be at least 200. There is no penalty for going over these numbers, but there is a penalty for padding your work to meet the minimums.
Part 1 is worth 45 points, and part 2 is worth 55.
Reference the slides from lecture 4.
Good luck!