devbox
知新_RL
这个屌丝很懒，什么也没留下！
关注作者
热门标签
热门文章
当前位置:   article > 正文

结合DVWA-Brute Force（暴力破解）_登录密码brute force

作者：知新_RL | 2024-06-16 11:53:46

赞

踩

登录密码brute force

Brute Force（暴力破解）：指的是黑客利用密码字典，使用穷举法猜解出用户的口令。

一、Low：

        看下核心源码：这里对username、password都未进行过滤，isset()函数只是检查参数是否被设置，返回True或者False。且后面将username、password这两个参数带入数据库查询，故存在SQL注入的漏洞。故有两种方法：（1）抓包用burp suite爆破；（2）手工SQL注入。

1.用burp suite爆破

  1. <?php
  2.  
  3. if( isset( $_GET[ 'Login' ] ) ) {
  4. 	// Get username
  5. 	$user = $_GET[ 'username' ];
  6.  
  7. 	// Get password
  8. 	$pass = $_GET[ 'password' ];
  9. 	$pass = md5( $pass );
  10.  
  11. 	// Check the database
  12. 	$query  = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
  13. 	$result = mysqli_query($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>' );
  14.  
  15. 	if( $result && mysqli_num_rows( $result ) == 1 ) {
  16. 		// Get users details
  17. 		$row    = mysqli_fetch_assoc( $result );
  18. 		$avatar = $row["avatar"];
  19.  
  20. 		// Login successful
  21. 		$html .= "<p>Welcome to the password protected area {$user}</p>";
  22. 		$html .= "<img src=\"{$avatar}\" />";
  23. 	}
  24. 	else {
  25. 		// Login failed
  26. 		$html .= "<pre><br />Username and/or password incorrect.</pre>";
  27. 	}
  28.  
  29. 	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
  30. }
  31.  
  32. ?>

 随便输入一个密码111抓个数据包，右键发送到Intruder模块：

        选择Attack type为：Cluster bomb。这里要破解username、password，故点击clear§，清除包里变量两边的§，然后在username、password等号后的内容两侧加上§，表示要破解这个参数。

        点击Payload，设置Paylosd set为1，type为Simple list，点击load添加字典username.txt文件。设置Payload set为2，type为Simple list，点击load添加字典Password.txt文件。（为节省执行时间，我选了几个密码和用户名，实际上应该用大字典）

        点击Start attack开始攻击。一般长度不一致的就是密码。这里是password。再看下返回的数据包，故password是正确密码。正确的用户名和密码会数据包会返回：Welcome to the password protected area admin。如下图：

错误的用户名或者密码返回的数据包会提示：Username and/or password incorrect。如下图：

 2.手工SQL注入。

        代码中未过滤username和password参数，在username出注入。在登录框输入：1，查询成功。输入1' and '1' ='1或者1' and 1=1#，成功。输入1' and '1' ='2或者1' and 1=2#，返回为空。故为单引号字符型注入。

 猜解字段数：1' order by 1# 和 1' order by 2# 均成功查询，但是 1' order by 3#  失败，或者用 -1' union select 1,2# 查询成功，用-1' union select 1,2,3# ，查询失败。故字段数为2。

 返回1和2，说明1处字段为Firstname，2处为Surname。且1和2处均可注入。获取当前数据库和版本号：-1' union select database(),version()#  ，当前数据为：dvwa ，版本为：5.7.26。

 获取数据库中的表：-1' union select 1,group_concat(table_name) from information_schema.tables where table_schema=database() #    表为guestbook、users。

获取表中的字段名：-1' union select 1,group_concat(column_name) from information_schema.columns where table_name='users' # 

字段有：user_id、first_name、last_name、user、password、avatar、last_login、failed_login、USER、CURRENT_CONNECTIONS、TOTAL_CONNECTIONS、id、username、password、level、id、username、password。

获取用户数据：-1' union select group_concat(user_id,first_name,last_name),group_concat(last_login,password) from users #

 二、medium

        看下代码：mysqli_real_escape_string()函数对字符串中的特殊符号（x00 / n / r / ' / " / xla）进行转义，抵抗SQL注入攻击。但是如果MYSQL5.5.37以下版本，若设置编码为GBK，能绕过该函数对单引号的转义；$pass做了MD5校验，但未防止做暴力破解机制。虽然sleep()函数，登录失败一次会有2秒延迟，但并不能阻止暴力破解攻击。故用burp suite暴力破解（和low级别流程类似，由于sleep()函数，会比较慢）。

  1. <?php
  2.  
  3. if( isset( $_GET[ 'Login' ] ) ) {
  4. 	// Sanitise username input
  5. 	$user = $_GET[ 'username' ];
  6. 	$user = ((isset($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)) ? "" : ""));
  7.  
  8. 	// Sanitise password input
  9. 	$pass = $_GET[ 'password' ];
  10. 	$pass = ((isset($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)) ? "" : ""));
  11. 	$pass = md5( $pass );
  12.  
  13. 	// Check the database
  14. 	$query  = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
  15. 	$result = mysqli_query($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>' );
  16.  
  17. 	if( $result && mysqli_num_rows( $result ) == 1 ) {
  18. 		// Get users details
  19. 		$row    = mysqli_fetch_assoc( $result );
  20. 		$avatar = $row["avatar"];
  21.  
  22. 		// Login successful
  23. 		$html .= "<p>Welcome to the password protected area {$user}</p>";
  24. 		$html .= "<img src=\"{$avatar}\" />";
  25. 	}
  26. 	else {
  27. 		// Login failed
  28. 		sleep( 2 );
  29. 		$html .= "<pre><br />Username and/or password incorrect.</pre>";
  30. 	}
  31.  
  32. 	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
  33. }
  34.  
  35. ?>

三、high

        看下核心源码：stripslashes()函数去除字符串中的反斜线（多个只去除一个），mysqli_real_escape_string()函数对字符串中的特殊符号（x00 / n / r / ' / " / xla）进行转义，抵抗SQL注入攻击。这里加入token，用来抵抗CSRF攻击。每次服务器返回登录页面，浏览器会发送给用户一个新的token值，用户发送登录请求时，需要同时上传token值。所以burp suite直接爆破不行了。

  1. <?php
  2.  
  3. if( isset( $_GET[ 'Login' ] ) ) {
  4. 	// Check Anti-CSRF token
  5. 	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
  6.  
  7. 	// Sanitise username input
  8. 	$user = $_GET[ 'username' ];
  9. 	$user = stripslashes( $user );
  10. 	$user = ((isset($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)) ? "" : ""));
  11.  
  12. 	// Sanitise password input
  13. 	$pass = $_GET[ 'password' ];
  14. 	$pass = stripslashes( $pass );
  15. 	$pass = ((isset($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)) ? "" : ""));
  16. 	$pass = md5( $pass );
  17.  
  18. 	// Check database
  19. 	$query  = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
  20. 	$result = mysqli_query($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>' );
  21.  
  22. 	if( $result && mysqli_num_rows( $result ) == 1 ) {
  23. 		// Get users details
  24. 		$row    = mysqli_fetch_assoc( $result );
  25. 		$avatar = $row["avatar"];
  26.  
  27. 		// Login successful
  28. 		$html .= "<p>Welcome to the password protected area {$user}</p>";
  29. 		$html .= "<img src=\"{$avatar}\" />";
  30. 	}
  31. 	else {
  32. 		// Login failed
  33. 		sleep( rand( 0, 3 ) );
  34. 		$html .= "<pre><br />Username and/or password incorrect.</pre>";
  35. 	}
  36.  
  37. 	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
  38. }
  39.  
  40. // Generate Anti-CSRF token
  41. generateSessionToken();
  42.  
  43. ?>

待补充

四、impossible

看下核心源码：当用户输入错的登录信息3次，锁定15秒，当用户多次登录失败，锁定该账户，故防止了暴力破解。

  1. <?php
  2.  
  3. if( isset( $_POST[ 'Login' ] ) && isset ($_POST['username']) && isset ($_POST['password']) ) {
  4. 	// Check Anti-CSRF token
  5. 	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
  6.  
  7. 	// Sanitise username input
  8. 	$user = $_POST[ 'username' ];
  9. 	$user = stripslashes( $user );
  10. 	$user = ((isset($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)) ? "" : ""));
  11.  
  12. 	// Sanitise password input
  13. 	$pass = $_POST[ 'password' ];
  14. 	$pass = stripslashes( $pass );
  15. 	$pass = ((isset($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)) ? "" : ""));
  16. 	$pass = md5( $pass );
  17.  
  18. 	// Default values
  19. 	$total_failed_login = 3;
  20. 	$lockout_time       = 15;
  21. 	$account_locked     = false;
  22.  
  23. 	// Check the database (Check user information)
  24. 	$data = $db->prepare( 'SELECT failed_login, last_login FROM users WHERE user = (:user) LIMIT 1;' );
  25. 	$data->bindParam( ':user', $user, PDO::PARAM_STR );
  26. 	$data->execute();
  27. 	$row = $data->fetch();
  28.  
  29. 	// Check to see if the user has been locked out.
  30. 	if( ( $data->rowCount() == 1 ) && ( $row[ 'failed_login' ] >= $total_failed_login ) )  {
  31. 		// User locked out.  Note, using this method would allow for user enumeration!
  32. 		//$html .= "<pre><br />This account has been locked due to too many incorrect logins.</pre>";
  33.  
  34. 		// Calculate when the user would be allowed to login again
  35. 		$last_login = strtotime( $row[ 'last_login' ] );
  36. 		$timeout    = $last_login + ($lockout_time * 60);
  37. 		$timenow    = time();
  38.  
  39. 		/*
  40. 		print "The last login was: " . date ("h:i:s", $last_login) . "<br />";
  41. 		print "The timenow is: " . date ("h:i:s", $timenow) . "<br />";
  42. 		print "The timeout is: " . date ("h:i:s", $timeout) . "<br />";
  43. 		*/
  44.  
  45. 		// Check to see if enough time has passed, if it hasn't locked the account
  46. 		if( $timenow < $timeout ) {
  47. 			$account_locked = true;
  48. 			// print "The account is locked<br />";
  49. 		}
  50. 	}
  51.  
  52. 	// Check the database (if username matches the password)
  53. 	$data = $db->prepare( 'SELECT * FROM users WHERE user = (:user) AND password = (:password) LIMIT 1;' );
  54. 	$data->bindParam( ':user', $user, PDO::PARAM_STR);
  55. 	$data->bindParam( ':password', $pass, PDO::PARAM_STR );
  56. 	$data->execute();
  57. 	$row = $data->fetch();
  58.  
  59. 	// If its a valid login...
  60. 	if( ( $data->rowCount() == 1 ) && ( $account_locked == false ) ) {
  61. 		// Get users details
  62. 		$avatar       = $row[ 'avatar' ];
  63. 		$failed_login = $row[ 'failed_login' ];
  64. 		$last_login   = $row[ 'last_login' ];
  65.  
  66. 		// Login successful
  67. 		$html .= "<p>Welcome to the password protected area <em>{$user}</em></p>";
  68. 		$html .= "<img src=\"{$avatar}\" />";
  69.  
  70. 		// Had the account been locked out since last login?
  71. 		if( $failed_login >= $total_failed_login ) {
  72. 			$html .= "<p><em>Warning</em>: Someone might of been brute forcing your account.</p>";
  73. 			$html .= "<p>Number of login attempts: <em>{$failed_login}</em>.<br />Last login attempt was at: <em>${last_login}</em>.</p>";
  74. 		}
  75.  
  76. 		// Reset bad login count
  77. 		$data = $db->prepare( 'UPDATE users SET failed_login = "0" WHERE user = (:user) LIMIT 1;' );
  78. 		$data->bindParam( ':user', $user, PDO::PARAM_STR );
  79. 		$data->execute();
  80. 	} else {
  81. 		// Login failed
  82. 		sleep( rand( 2, 4 ) );
  83.  
  84. 		// Give the user some feedback
  85. 		$html .= "<pre><br />Username and/or password incorrect.<br /><br/>Alternative, the account has been locked because of too many failed logins.<br />If this is the case, <em>please try again in {$lockout_time} minutes</em>.</pre>";
  86.  
  87. 		// Update bad login count
  88. 		$data = $db->prepare( 'UPDATE users SET failed_login = (failed_login + 1) WHERE user = (:user) LIMIT 1;' );
  89. 		$data->bindParam( ':user', $user, PDO::PARAM_STR );
  90. 		$data->execute();
  91. 	}
  92.  
  93. 	// Set the last login time
  94. 	$data = $db->prepare( 'UPDATE users SET last_login = now() WHERE user = (:user) LIMIT 1;' );
  95. 	$data->bindParam( ':user', $user, PDO::PARAM_STR );
  96. 	$data->execute();
  97. }
  98.  
  99. // Generate Anti-CSRF token
  100. generateSessionToken();
  101.  
  102. ?>

声明：本文内容由网友自发贡献，不代表【wpsshop博客】立场，版权归原作者所有，本站不承担相应法律责任。如您发现有侵权的内容，请联系我们。转载请注明出处：https://www.wpsshop.cn/w/知新_RL/article/detail/726523
推荐阅读
相关标签

Copyright © 2003-2013 www.wpsshop.cn 版权所有，并保留所有权利。

  

闽ICP备14008679号