In Splunk SOAR versions below 8.6.0, an authenticated user with no role assigned could use the /rest/health endpoint to gather system and cluster telemetry that should be restricted to administrative or support users. The vulnerability is a missing authorization check, where the endpoint does not verify that the caller holds a role permitted to view system health and cluster state. For more information see Manage roles and permissions in Splunk SOAR (On-premises) (https://help.splunk.com/en/splunk-soar/soar-on-premises/administer-soar-on-premises/8.5.0/manage-your-splunk-soar-on-premises-users-and-accounts/manage-roles-and-permissions-in-splunk-soar-on-premises) and Monitor the health of your Splunk SOAR (On-premises) system (https://help.splunk.com/en/splunk-soar/soar-on-premises/administer-soar-on-premises/8.5.0/manage-your-splunk-soar-on-premises-system-health-and-performance/monitor-the-health-of-your-splunk-soar-on-premises-system) in the Splunk documentation.
Upgrade Splunk SOAR to 8.6.0 or higher.