Identify the weakness in the below JSP file:

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2  ...   
3  Dear User,   
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5  If you liked our services, then you would like to refer it to your friends.   
6    
7  Click on the below link:    
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9  <a href="/CWE/ReferAFriendAction?pageRedirect=">"&gt;  "Refer a Friend"!</a>  10  ...  
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