本文主要是介绍DVWA靶场-CSRF跨站请求伪造,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
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();?>
- 使用token机制
- 使用PDO(PHP 数据对象)来执行数据库查询和准备语句,以防止 SQL 注入攻击。
- 在处理密码更改请求时,首先验证当前用户输入的原始密码是否正确。
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