source: https://www.securityfocus.com/bid/17748/info
 
4Images is prone to multiple, unspecified SQL-injection vulnerabilities. These issues are due to a failure in the application to properly sanitize user-supplied input before using it in an SQL query. 
 
A successful exploit could allow an attacker to compromise the application, access or modify data, or exploit vulnerabilities in the underlying database implementation.

http://www.example.com/member.php?action=mailform&user_id=366&sessionid=[SQL]