Description: Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into otherwise benign and trusted websites. XSS attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user. Flaws that allow these attacks to succeed are quite widespread and occur anywhere a web application uses input from a user within the output it generates without validating or encoding it. An attacker can use XSS to send a malicious script to an unsuspecting user. The end user’s browser has no way to know that the script should not be trusted, and will execute the script. Because it thinks the script came from a trusted source, the malicious script can access any cookies, session tokens, or other sensitive information retained by the browser and used with that site. These scripts can even rewrite the content of the HTML page Reference to fix the issue: To prevent cross-site scripting vulnerabilities it is very important to apply a context dependent output encoding. In some cases it might be enough to encode the HTML special characters, such as opening and closing tags. In other cases a correctly applied URL encoding is necessary. Links should generally be disallowed if they don't begin with a whitelisted protocol such as http:// or https://, thus preventing the use of URI schemes such as javascript://. Even though most modern web browsers have an inbuilt XSS filter they should not be seen as an alternative to sanitization https://www.netsparker.com/blog/web-security/cross-site-scripting-xss/ Steps To reproduce: > Step 1: log into the demo store of X-Cart.com > Step 2: Browsed the below URL > https://demostore.x-cart.com/themes/igoods/?sortBy=p.arrivalDate&sortOrder=asc&sessionCell=XLiteModuleXCProductFilterViewItemsListProductCustomerCategoryCategoryFilter2%22%3E%3Cscript%3Ealert(1)%3C%2Fscript%3E > Step 3: You will get the XSS Popup alert