exactyl is a customisable game management panel and billing system. Commits after 025e8dbb0daaa04054276bda814d922cf4af58da and before e28edb204e80efab628d1241198ea4f079779cfd inject server-side objects into client-side JavaScript through resources/views/templates/wrapper.blade.php. Using unescaped {!! json_encode(...) !!} without safe encoding flags allows string values to break out of the JavaScript context and be interpreted as HTML/JS by the browser.
If any serialized fields contain attacker-controlled content, such as a username, display name, or site config value, a malicious payload will execute arbitrary script for any user viewing the page (stored DOM XSS). This issue has been patched by commit e28edb204e80efab628d1241198ea4f079779cfd.
Attack Parameters
Impact Assessment
CVSS Vector v3.1