A vulnerability, which was classified as critical, was found in SourceCodester Simple Invoice Generator System 1.0. Affected is an unknown function of the file /save_invoice.php. The manipulation of the argument invoice_code/customer/cashier/total_amount/discount_percentage/discount_amount/tendered_amount leads to sql injection. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.