Cross Site Scripting (XSS) in MyBB v1.8.20 allows remote attackers to inject arbitrary web script or HTML via the “Description” field found in the “Add New Forum” page by doing an authenticated POST HTTP request to ‘/Upload/admin/index.php?module=forum-management&action=add’.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-19049
Reference (s):
- https://github.com/joelister/bug/issues/2