Multiple cross-site scripting (XSS) vulnerabilities in SimpleInvoices before stable-2012-1-CIS3000 allow remote attackers to inject arbitrary web script or HTML via (1) the having parameter in a manage action to index.php; (2) the Email field in an Add User action; (3) the Customer Name field in an Add Customer action; the (4) Street address, (5) Street address 2, (6) City, (7) Zip code, (8) State, (9) Country, (10) Mobile Phone, (11) Phone, (12) Fax, (13) Email, (14) PayPal business name, (15) PayPal notify url, (16) PayPal return url, (17) Eway customer ID, (18) Custom field 1, (19) Custom field 2, (20) Custom field 3, or (21) Custom field 4 field in an Add Biller action; (22) the Customer field in an Add Invoice action; the (23) Invoice or (24) Notes field in a Process Payment action; (25) the Payment type description field in a Payment Types action; (26) the Description field in an Invoice Preferences action; (27) the Description field in a Manage Products action; or (28) the Description field in a Tax Rates action.