GHSA-9v82-vcjx-m76j: 
PHP vulnerability analysis and mitigation

A high-severity Reflective Cross-Site Scripting (XSS) vulnerability was discovered in Shopware CMS components, identified as GHSA-9v82-vcjx-m76j. The vulnerability affects Shopware versions >= 6.7.0.0 and < 6.7.2.1, and was patched in version 6.7.2.1. The issue stems from inadequate input validation in the JavaScript variable 'activeRouteParameters', specifically at the endpoints /page/cms/ and /widget/cms/ (GitHub Advisory).

The vulnerability has a CVSS v3.1 score of 8.8 (High), with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:L. The issue is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation). The vulnerability allows malicious actors to inject JavaScript code into URLs, which executes in the user's browser when visited. No user account is required to exploit this vulnerability (GitHub Advisory).

The exploitation of this XSS vulnerability enables attackers to perform harmful actions in the user's web browser within the session context of the affected user. Critical impacts include the potential theft of session tokens and administrative tokens, particularly concerning since sensitive cookies are not configured with the HttpOnly attribute and administrator JWTs are stored in sessionStorage. Attackers can obtain user session tokens and perform administrative actions when an administrative user is affected (GitHub Advisory).

The primary mitigation is to upgrade to Shopware version 6.7.2.1 which contains the security fix. For older versions of 6.7, security measures are available via a plugin. The fix involves properly escaping the JSON output in the storefront template (GitHub Release, GitHub Advisory).