web
Author: corb3nik
This is the most secure login form on earth.
We use SECURITY BY OBSCURITY in order to prevent hackers from finding our flags.
I dare you to login : http://localhost:17002
Requirements:
- docker
Start:
docker-compose upThis challenge requires us to find the username/password used in the login form.
When checking the source code of the HTML page, you'll see the following function.
function validate() {
[][(![]+[])[+[]]+([![]] ...
}
At first, this doesn't seem like valid JavaScript. In fact, this is obfuscated JavaScript resulting directly from a tool called JSFuck.
The gist of JSFuck is : using only 6 characters, we can create any character/string. It is also possible to obtain various objects/constructors through these same 6 characters. This allows us to create full working JavaScript scripts using only 6 chars.
You can see how its done here : https://github.com/aemkei/jsfuck/blob/master/jsfuck.js
To solve the challenge, we can paste the challenge script into JSUnfuck, revealing the following code :
if (document.forms[0].username.value == "corb3nik" && document.forms[0].password.value == "chickenachos") document.location = "4d4932602a75414640946d38ea6fefbf.php"
The flag is located at http://localhost:17002/4d4932602a75414640946d38ea6fefbf.php