Brute Force——暴力破解
low
源代码:
<?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);
}
?>
代码直接获取用户输入的用户名和密码,密码在用md5加一下密
先将DVWA设置为Low级别,然后在登陆界面随意输入用户名和密码,设置代理截取数据包,然后右键点击发送至Intruder
选择攻击方式为Cluster bomb,并设置用户名和密码位置为攻击位置,在此我设置的是假设用户名和密码都不知道的情况下进行暴力破解,不过非常耗时,一般往往都是针对某一用户名爆破密码,攻击方式设置为sniper即可,详情参考前文burpsuite——intruder
而后设置Payloads,Payload set 1设置为usernames,Payload set 2设置为passwords,设置好后,点击右上角的start attack开始攻击,当然了,这样会经历一个非常非常非常漫长的过程,也可以直接假设用户名为admin只使用sniper模式暴力破解密码(参考前文BurpSuite——Intruder)也可以自己填几个用户名和密码进行模拟实验。
在实验中,我仅填了几个用户名和密码,其中包括真实用户名和密码,之后匹配length长度,找出特殊的那个,即为正确用户名和密码
medium
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 = $row["avatar"];
// Login successful
echo "<p>Welcome to the password protected area {$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);
}
?>
这个级别利用函数mysqli_real_escape_string()进行了一些特殊字符的转义,抵御sql注入,并且如果密码错误的话,会加一个2秒的延时,但是思路和上一级别相同,只不过更慢了而已
因为时间关系,这次就只设置一个攻击位置,使用sniper攻击方式
设置好payloads后进行攻击即可,然后在根据length判断密码
high
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 = $row["avatar"];
// Login successful
echo "<p>Welcome to the password protected area {$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();
?>
同样利用mysqli_real_escape_string()函数进行了一些特殊字符的转义,并且用stripslashes()函数去除掉了string字符的反斜杠,抵御sql注入以及xss
high级别增加了Anti-CSRF token,用来抵御CSRF攻击,但每次提交都会有一个随机的user_token
可以看到,即使提交的用户名和密码相同,user_token也是不同的,再次抓包发送至intruder,并选择pitchfork模式,设置密码和token值为攻击点
然后将Grep-Extract按下图这样设置
在设置总是允许重定向,并设置单线程攻击
设置payloads,第一个攻击位置和之前一样设置,只设置几个密码即可(适当的时候让电脑偷个懒)
第二个攻击位置设置成Recursive grep,并将之前获得的token值复制过来,点击start attack即可
然后找到结果即可
impossible
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();
?>
这个不可能等级在high等级的基础上限制了登录次数,登录失败三次就会锁住账号15s,同时采用了PDO防御sql注入
Command Injection——命令注入
low
源代码:
<?php
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 ' . $target );
}
// Feedback for the end user
echo "<pre>{$cmd}</pre>";
}
?>
执行ping命令,但未对输入进行过滤,利用符号连接请求
medium
源代码:
<?php
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 ' . $target );
}
// Feedback for the end user
echo "<pre>{$cmd}</pre>";
}
?>
使用了黑名单策略,对&&和;进行了转义,黑名单即不允许输入什么,但是往往存在其他方式利用漏洞
command1 && command2表示先执行1,成功后执行2,否则不执行2
command1 && command2表示先执行1,不管是否成功都执行2
所以即使上图中command1位置输入有误也会执行command2位置的命令
high
源代码:
<?php
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 ' . $target );
}
// Feedback for the end user
echo "<pre>{$cmd}</pre>";
}
?>
我们可以看到,这次过滤的字符比较多,进一步完善了黑名单,但仍然有缺陷
这个竖线后面有一个明显的空格,所以我们可以用 | 拼接两个命令,前后不留空格即可
command1 | command2表示将command1的输出作为command2的输入,并且只打印command2的结果
impossible
源代码:
<?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 ' . $target );
}
// Feedback for the end user
echo "<pre>{$cmd}</pre>";
}
else {
// Ops. Let the user name theres a mistake
echo '<pre>ERROR: You have entered an invalid IP.</pre>';
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
stripslashes()函数回删除字符串中的反斜杠,返回没有反斜杠的字符串
explode()函数把字符串分散成数组
执行的差不多是白名单的思路,只有数字.数字.数字.数字才会被接收执行
CSRF——跨站请求伪造
low
源代码:
<?php
if( isset( $_GET[ 'Change' ] ) ) {
// Get input
$pass_new = $_GET[ 'password_new' ];
$pass_conf = $_GET[ 'password_conf' ];
// Do the passwords match?
if( $pass_new == $pass_conf ) {
// They do!
$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$pass_new = md5( $pass_new );
// Update the database
$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $insert ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );
// Feedback for the user
echo "<pre>Password Changed.</pre>";
}
else {
// Issue with passwords matching
echo "<pre>Passwords did not match.</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
可以看到只需要新密码与确认密码两栏相同就可以将密码更改, 所以我们可以制作一个请求链接来钓鱼http://192.168.61.128/dvwa/vulnerabilities/csrf/?password_new=password&password_conf=password&Change=Change#
只要用户点击这个链接,网页就会显示password changed,并且将密码改为password,我们的目的也就达到了
它利用用户的身份,诱使用户点击了相关链接,从而达到修改用户密码的过程。
比如说一个不知名的网站恰好存在此漏洞,黑客给目标用户发送钓鱼链接,等待用户登陆成功上线后收到消息,然后打开链接,那么该用户的密码则会被修改,因为链接上存在修改密码的参数,大部分用户可能会猜到,所以黑客往往需要将其隐藏,比如重新构造一个网站或者生成一个短链接等。
诱使用户访问这个链接同样能够达到攻击效果
medium
源代码:
<?php
if( isset( $_GET[ 'Change' ] ) ) {
// Checks to see where the request came from
if( stripos( $_SERVER[ 'HTTP_REFERER' ] ,$_SERVER[ 'SERVER_NAME' ]) !== false ) {
// Get input
$pass_new = $_GET[ 'password_new' ];
$pass_conf = $_GET[ 'password_conf' ];
// Do the passwords match?
if( $pass_new == $pass_conf ) {
// They do!
$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
$pass_new = md5( $pass_new );
// Update the database
$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";
$result = mysqli_query($GLOBALS["___mysqli_ston"], $insert ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );
// Feedback for the user
echo "<pre>Password Changed.</pre>";
}
else {
// Issue with passwords matching
echo "<pre>Passwords did not match.</pre>";
}
}
else {
// Didn't come from a trusted source
echo "<pre>That request didn't look correct.</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
?>
相比low级别,这个级别验证了请求头中的referer字段,请求必须带有服务器IP地址才能发出,如果使用上一级别构造的url,报错如下
我们正常修改密码时抓包如下
在输入构造的url抓包如下,发现并没有referer参数
尝试手动加入一个,胡乱写了地址,但是包含了目标IP
成功修改了密码,然后按照low级别所讲的构造一个页面,在按照刚才的方法操作即可
high
源代码:
<?php
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"], $insert ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );
// Feedback for the user
echo "<pre>Password Changed.</pre>";
}
else {
// Issue with passwords matching
echo "<pre>Passwords did not match.</pre>";
}
((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}
// Generate Anti-CSRF token
generateSessionToken();
?>
与前两个级别相比,这个级别加入了anti-csrf token,每次修改密码时都会返回一个随机的token参数,发起请求必须要提交该参数,服务器在处理时先查验token参数是否正确,然后决定是否修改密码
同样的,抓包查看
要完成此题,需要获取token值,所以需要构造代码,先获取token值,然后再改密码
浏览器的同源策略不允许跨域请求,看其他人的完成过程,发现可以结合xss一同攻击,在此不再叙述。
impossible
源代码:
<?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 "<pre>Password Changed.</pre>";
}
else {
// Issue with passwords matching
echo "<pre>Passwords did not match or current password incorrect.</pre>";
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
需要输入原始密码,从根上解决了这一问题
File Inclusion——文件包含
low
源代码:
<?php
// The page we wish to display
$file = $_GET[ 'page' ];
?>
服务器没有做任何的过滤,按照网站开发人员的设想是,我们应该点击对应的链接跳转到对应的页面
点击file1.php对应的url为http://192.168.186.128/dvwa/vulnerabilities/fi/?page=file1.php
现在构造一个url http://192.168.186.128/dvwa/vulnerabilities/fi/?page=vegetable
服务器肯定是没有vegetable这个文件的,如果存在文件包含漏洞,就会出现如下结果
可以看到,页面报错显示出了正确的文件路径
构造url http://192.168.186.128/dvwa/vulnerabilities/fi/page=C:\phpStudy\PHPTutorial\WWW\dvwa\php.ini可以发现我们读取了php相关配置,这肯定是不被允许的
不仅如此,也可以使用../../../../来读取相对路径的内容,使用../是为了进入c盘根目录
除此之外,如果allow_url_fopen与allow_url_include开启的话,还可以还包含远程服务器上的文件在?page后加一个http://……即可,在此条件不足不进行演示
medium
源代码:
<?php
// The page we wish to display
$file = $_GET[ 'page' ];
// Input validation
$file = str_replace( array( "http://", "https://" ), "", $file );
$file = str_replace( array( "../", "..\"" ), "", $file );
?>
可以看到代码过滤了http://,https://以及 ../ ..\,将其替换为空字符,但是str_replace可以通过双写绕过比如?page=http://……,此时会被过滤,但是可以写成?page=hthttp://tp://,代码将http://删除后,前后拼合依旧是http://
而../同样可以利用 ..././ 来绕过,如图所示
high
源代码:
<?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;
}
?>
从代码看出,使用了!fmatch函数检查?page后的参数,要求page开头的参数必须是file才行,这时,我们随便输一个值时,页面返回如下
使用之前构造的url也是一样的结果,但在这里可以利用file协议来绕过,我们在浏览器中可以直接打开本地内容,比如打开我刚刚存在桌面的.txt文件
同样的思路,构造?page=后的参数为 file://C:/phpStudy/PHPTutorial/WWW/1.html 即可和刚才一样成功利用漏洞‘
impossible
源代码:
<?php
// 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;
}
?>
可以看使用了白名单,依然从根上解决了问题,?page后的参数是规定好的,不可以更改,白名单yyds
File Upload——文件上传
low
源代码:
<?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' ] );
// Can we move the file to the upload folder?
if( !move_uploaded_file( $_FILES[ 'uploaded' ][ 'tmp_name' ], $target_path ) ) {
// No
echo '<pre>Your image was not uploaded.</pre>';
}
else {
// Yes!
echo "<pre>{$target_path} succesfully uploaded!</pre>";
}
}
?>
代码非常简单,没有对上传文件进行任何形式的过滤,存在很明显的文件上传漏洞
我们可以在txt文件中写上一句话木马,然后将后缀改为 .php 进行上传
很容易的就上传成功了,并且给出了上传路径
然后使用菜刀等工具进行连接即可
medium
源代码:
<?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' ], $target_path ) ) {
// No
echo '<pre>Your image was not uploaded.</pre>';
}
else {
// Yes!
echo "<pre>{$target_path} succesfully uploaded!</pre>";
}
}
else {
// Invalid file
echo '<pre>Your image was not uploaded. We can only accept JPEG or PNG images.</pre>';
}
}
?>
服务器对上传文件的大小和类型做了限制,只能上传文件类型为jpeg或png格式的文件,且大小小于100000字节
在此,依然上传刚才的 1.php 文件,然后用burpsuite抓包,修改文件类型即可
可以看到上传成功,在用菜刀等工具连接即可
high
源代码:
<?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_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, $target_path ) ) {
// No
echo '<pre>Your image was not uploaded.</pre>';
}
else {
// Yes!
echo "<pre>{$target_path} succesfully uploaded!</pre>";
}
}
else {
// Invalid file
echo '<pre>Your image was not uploaded. We can only accept JPEG or PNG images.</pre>';
}
}
?>
使用函数检测上传文件是否为图片格式,并约束文件后缀名必须为jpg、jpeg、png结尾。也就是文件格式和文件内容都必须是图片才可以
在命令行中使用 copy /b 1.png+1.php 2.png 将一句话木马与图片相结合
但是此时无法直接用菜刀链接,可以结合其他漏洞一起进行利用
impossible
源代码:
<?php
if( isset( $_POST[ 'Upload' ] ) ) {
// Check Anti-CSRF token
checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
// File information
$uploaded_name = $_FILES[ 'uploaded' ][ 'name' ];
$uploaded_ext = substr( $uploaded_name, strrpos( $uploaded_name, '.' ) + 1);
$uploaded_size = $_FILES[ 'uploaded' ][ 'size' ];
$uploaded_type = $_FILES[ 'uploaded' ][ 'type' ];
$uploaded_tmp = $_FILES[ 'uploaded' ][ 'tmp_name' ];
// Where are we going to be writing to?
$target_path = DVWA_WEB_PAGE_TO_ROOT . 'hackable/uploads/';
//$target_file = basename( $uploaded_name, '.' . $uploaded_ext ) . '-';
$target_file = md5( uniqid() . $uploaded_name ) . '.' . $uploaded_ext;
$temp_file = ( ( ini_get( 'upload_tmp_dir' ) == '' ) ? ( sys_get_temp_dir() ) : ( ini_get( 'upload_tmp_dir' ) ) );
$temp_file .= DIRECTORY_SEPARATOR . md5( uniqid() . $uploaded_name ) . '.' . $uploaded_ext;
// Is it an image?
if( ( strtolower( $uploaded_ext ) == 'jpg' || strtolower( $uploaded_ext ) == 'jpeg' || strtolower( $uploaded_ext ) == 'png' ) &&
( $uploaded_size < 100000 ) &&
( $uploaded_type == 'image/jpeg' || $uploaded_type == 'image/png' ) &&
getimagesize( $uploaded_tmp ) ) {
// Strip any metadata, by re-encoding image (Note, using php-Imagick is recommended over php-GD)
if( $uploaded_type == 'image/jpeg' ) {
$img = imagecreatefromjpeg( $uploaded_tmp );
imagejpeg( $img, $temp_file, 100);
}
else {
$img = imagecreatefrompng( $uploaded_tmp );
imagepng( $img, $temp_file, 9);
}
imagedestroy( $img );
// Can we move the file to the web root from the temp folder?
if( rename( $temp_file, ( getcwd() . DIRECTORY_SEPARATOR . $target_path . $target_file ) ) ) {
// Yes!
echo "<pre><a href='${target_path}${target_file}'>${target_file}</a> succesfully uploaded!</pre>";
}
else {
// No
echo '<pre>Your image was not uploaded.</pre>';
}
// Delete any temp files
if( file_exists( $temp_file ) )
unlink( $temp_file );
}
else {
// Invalid file
echo '<pre>Your image was not uploaded. We can only accept JPEG or PNG images.</pre>';
}
}
// Generate Anti-CSRF token
generateSessionToken();
?>
直接对上传的文件进行了重命名并且防护csrf攻击,对文件内容进行了严格的筛查