source: https://www.securityfocus.com/bid/13560/info CodeThatShoppingCart is reportedly affected by multiple input validation vulnerabilities. These issues may allow remote attackers to carry out cross-site scripting and SQL injection attacks. An attacker may also potentially disclose sensitive data. CodeThatShoppingCart 1.3.1 was reported to be vulnerable. Other versions may be affected as well. http://www.example.com/shoppingcart/catalog.php?action=category_show &id=1%20or%20like%20%60a%%60 http://www.example.com/shoppingcart/demo/catalog.php?action= category_show&id=1%20or%201=1