DVWA靶场-CSRF跨站请求伪造-编程知识

CSRF(跨站请求伪造)简介
概念

CSRF（Cross—site request forgery），跨站请求伪造，是指利用受害者未失效的身份认证信息（cookie，会话等），诱骗其点击恶意链接或者访问包含攻击代码的页面，在受害人不知情的情况下，以受害者的身份向（身份认证信息所对应的）服务器发送请求，从而完成非法操作（如转账，改密等）。

CSRF与XSS的区别

CSRF属于业务逻辑漏洞，在服务器看来，所有的请求都是合法正常的；

XSS，SQL注入等等都是属于技术漏洞；

XSS：客户信任服务器；

CSRF：服务器信任客户（经过身份认证的）；

CSRF攻击成功的前提

用户必须登录；

黑客必须懂得一些发包的请求；

服务器端不会有二次认证；

被害者是不知情的；

危害

修改用户信息，如用户头像、发货地址等

个人隐私泄露，机密资料泄露

执行恶意操作，如修改密码，购买商品，转账等（盗用受害者身份，受害者能做什么攻击者就能以受害者身份）

具体操作请看这篇文章pikachu靶场-csrf_pikachu csrf黑名单-CSDN博客

low等级

<?phpif( isset( $_GET[ 'Change' ] ) ) {// Get input$pass_new  = $_GET[ 'password_new' ];$pass_conf = $_GET[ 'password_conf' ];// Do the passwords match?if( $pass_new == $pass_conf ) {// They do!$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));$pass_new = md5( $pass_new );// Update the database$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";$result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );// Feedback for the user$html .= "<pre>Password Changed.</pre>";}else {// Issue with passwords matching$html .= "<pre>Passwords did not match.</pre>";}((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}?>

只是对输入的pass_new和pass_conf进行了==比较，没有进行其他的防御，因此，只要用户在cookie还有效的时间内在相同的浏览器访问我们给定的url（该操作是服务器对请求的发送者进行了身份验证，检查cookie），就可以实现CSRF 攻击，最终修改密码。

medium等级

<?phpif( isset( $_GET[ 'Change' ] ) ) {// Checks to see where the request came fromif( stripos( $_SERVER[ 'HTTP_REFERER' ] ,$_SERVER[ 'SERVER_NAME' ]) !== false ) {// Get input$pass_new  = $_GET[ 'password_new' ];$pass_conf = $_GET[ 'password_conf' ];// Do the passwords match?if( $pass_new == $pass_conf ) {// They do!$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));$pass_new = md5( $pass_new );// Update the database$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";$result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );// Feedback for the user$html .= "<pre>Password Changed.</pre>";}else {// Issue with passwords matching$html .= "<pre>Passwords did not match.</pre>";}}else {// Didn't come from a trusted source$html .= "<pre>That request didn't look correct.</pre>";}((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}?>

使用$_SERVER['HTTP_REFERER']获取请求的来源页面URL。
使用$_SERVER['SERVER_NAME']获取当前服务器的域名。
使用stripos()函数（不区分大小写地查找字符串首次出现的位置）来检查请求来源URL是否包含当前服务器的域名。

假如服务器地址为192.168.101.66，即为SERVER_NAME，我们只需要把我们构造的恶意页面文件名改为192.168.101.66.html，HTTP_REFERER就会包含192.168.101.66.html,就可以绕过stripos了。

这个对于本地搭建的DVWA是无效的

high等级

<?php$change = false;
$request_type = "html";
$return_message = "Request Failed";if ($_SERVER['REQUEST_METHOD'] == "POST" && array_key_exists ("CONTENT_TYPE", $_SERVER) && $_SERVER['CONTENT_TYPE'] == "application/json") {$data = json_decode(file_get_contents('php://input'), true);$request_type = "json";if (array_key_exists("HTTP_USER_TOKEN", $_SERVER) &&array_key_exists("password_new", $data) &&array_key_exists("password_conf", $data) &&array_key_exists("Change", $data)) {$token = $_SERVER['HTTP_USER_TOKEN'];$pass_new = $data["password_new"];$pass_conf = $data["password_conf"];$change = true;}
} else {if (array_key_exists("user_token", $_REQUEST) &&array_key_exists("password_new", $_REQUEST) &&array_key_exists("password_conf", $_REQUEST) &&array_key_exists("Change", $_REQUEST)) {$token = $_REQUEST["user_token"];$pass_new = $_REQUEST["password_new"];$pass_conf = $_REQUEST["password_conf"];$change = true;}
}if ($change) {// Check Anti-CSRF tokencheckToken( $token, $_SESSION[ 'session_token' ], 'index.php' );// Do the passwords match?if( $pass_new == $pass_conf ) {// They do!$pass_new = mysqli_real_escape_string ($GLOBALS["___mysqli_ston"], $pass_new);$pass_new = md5( $pass_new );// Update the database$insert = "UPDATE `users` SET password = '" . $pass_new . "' WHERE user = '" . dvwaCurrentUser() . "';";$result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert );// Feedback for the user$return_message = "Password Changed.";}else {// Issue with passwords matching$return_message = "Passwords did not match.";}mysqli_close($GLOBALS["___mysqli_ston"]);if ($request_type == "json") {generateSessionToken();header ("Content-Type: application/json");print json_encode (array("Message" =>$return_message));exit;} else {$html .= "<pre>" . $return_message . "</pre>";}
}// Generate Anti-CSRF token
generateSessionToken();?>

设置了token限制，它是在每次访问此页面时，会随机生成一个token，当发起服务器请求时服务器会检查它的值。

思路：先获取token的值，再构造链接并诱骗受害者访问。

利用以下payload在反射型xss中获取到token值，不要点确认（否则会重新生成新的token）

<iframe src='../csrf/' onload="alert(frames[0].document.getElementsByName('user_token')
[0].value)">

在 bp抓包中替换掉已经抓到的token即可实现修改密码

Impossible等级

<?phpif( isset( $_GET[ 'Change' ] ) ) {// Check Anti-CSRF tokencheckToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );// Get input$pass_curr = $_GET[ 'password_current' ];$pass_new  = $_GET[ 'password_new' ];$pass_conf = $_GET[ 'password_conf' ];// Sanitise current password input$pass_curr = stripslashes( $pass_curr );$pass_curr = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_curr ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));$pass_curr = md5( $pass_curr );// Check that the current password is correct$data = $db->prepare( 'SELECT password FROM users WHERE user = (:user) AND password = (:password) LIMIT 1;' );$data->bindParam( ':user', dvwaCurrentUser(), PDO::PARAM_STR );$data->bindParam( ':password', $pass_curr, PDO::PARAM_STR );$data->execute();// Do both new passwords match and does the current password match the user?if( ( $pass_new == $pass_conf ) && ( $data->rowCount() == 1 ) ) {// It does!$pass_new = stripslashes( $pass_new );$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));$pass_new = md5( $pass_new );// Update database with new password$data = $db->prepare( 'UPDATE users SET password = (:password) WHERE user = (:user);' );$data->bindParam( ':password', $pass_new, PDO::PARAM_STR );$data->bindParam( ':user', dvwaCurrentUser(), PDO::PARAM_STR );$data->execute();// Feedback for the user$html .= "<pre>Password Changed.</pre>";}else {// Issue with passwords matching$html .= "<pre>Passwords did not match or current password incorrect.</pre>";}
}// Generate Anti-CSRF token
generateSessionToken();?>