CSRF

CSRF

一、定义:CSRF(cross-site request forgery):跨站请求伪造,是指利用受害者尚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)。
二、攻击特点:攻击者盗用用户的身份,以用户的名义进行某些非法操作

DVWA

一、low:在这里插入图片描述

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<?php

if( 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
echo "<pre>Password Changed.</pre>";
}
else {
// Issue with passwords matching
echo "<pre>Passwords did not match.</pre>";
}

((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

首先按照流程修改密码,发现url改变http://127.0.0.1/dvwa/vulnerabilities/csrf/?password_new=123&password_conf=123&Change=Change#
查看源码,没有任何防护,可直接通过修改URL修改密码
二、medium(需要使用到hackbar)
查看源码,可知先检测refer是否包含主机名称,再进行更改密码

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<?php

if( isset( $_GET[ 'Change' ] ) ) {
// Checks to see where the request came from
if( 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
echo "<pre>Password Changed.</pre>";
}
else {
// Issue with passwords matching
echo "<pre>Passwords did not match.</pre>";
}
}
else {
// Didn't come from a trusted source
echo "<pre>That request didn't look correct.</pre>";
}

((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

在这里插入图片描述
在这里插入图片描述

漏洞利用

一、构造链接:http://127.0.0.1/dvwa/vulnerabilities/csrf/?password_new=123&password_conf=123&Change=Change#
二、利用短链接来隐藏URL(点击短链接,会自动跳转到真实网站)
因为本地搭的环境,服务器域名是ip所以无法生成相应的短链接= =,实际攻击场景下只要目标服务器的域名不是ip,是可以生成相应短链接的。
三、构造攻击页面
四、CSRF与XSS结合
将CSRF代码写入XSS注入点(最好是存储型)
< script
src= “http://127.0.0.1/dvwa/vulnerabilities/csrf/?password_new=123&password_conf=123&Change=Change#"></ script>
用户触发XSS,优点是更加具有隐蔽性,不会出现密码修改界面

函数

$_SERVER[ ‘HTTP_REFERER’ ]此函数用来判断用户提供的信息是否与127.0.0.1一致