CTF-- code audit coverage holes writeup of variables [2]

Topic :

 

 

 

Basis :

　　Basic knowledge needed to see variables coverage holes [1] 

 

Analysis :

       Now $ a = 'hi' , and must meet the following function $ a = 'jaivy' can output flag, you need to do is to find ways to overwrite the original value of $ a.

 

 

  

       Is then prompted, get outside a parameter assigned $$ $ = Key value , i.e. the value of the preceding sentence $ a cover by an external assignment, when the external input is: A = jaivy when the statement is: $ a jaivy = , corresponds to the beginning of the target, the condition.

 

Payload：

 

 

 

 

If wrong, please correct me, thank you!