In Splunk Enterprise versions below 10.4.4, 10.2.8, 10.0.11, and 9.4.16, and Splunk Secure Gateway versions below 3.10.12, 3.9.26, and 3.8.73, a user who does not hold the "admin" or "power" Splunk roles could view dashboard and report listings beyond the requested filter scope while remaining within objects that the user can access.
The vulnerability is possible because Splunk Secure Gateway does not neutralize special characters in values before it creates filters for dashboard and report requests.
For more information see About configuring role-based user access (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.2/manage-splunk-platform-users-and-roles/about-configuring-role-based-user-access) in the Splunk documentation.