Big Number

Big Number

a big number is needed to save the world

• Link: http://35.240.62.111/bignumber/

Solve:

• Steps

  • After connecting to the webpage, it will ask you to enter 3 numbers that exceed the value 999.

  • If we clicked source, the source of the php will appear as shown below:

      <?php if (isset($_GET['password'])) {
          if (is_numeric($_GET['password'])){
              if (strlen($_GET['password']) < 4){
                  if ($_GET['password'] > 999)
                      die($flag);
                  else
                      print 'Too little';
              } else
                      print 'Too long';
          } else
              print 'Password is not numeric';
      }
      ?> 
    

  • After taking a look at the source code, I searched about the is_numeric function in php, notice we can put the letter e as an exponential. Example: 2e2 = 4

  • Now we knew how is_numeric function workd, we can put in the box a value that way more biger that 999 like:

      9e9
    

Flag: FLAG{Yes_Y0u_C4n_Use_Exp0nentiaL}