Server-Side Request Forgery (SSRF) through the Report Notifications REST API in Splunk Secure Gateway

In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, and Splunk Secure Gateway versions below 3.10.9, 3.9.23, and 3.8.70, a user who does not hold the "admin" or "power" Splunk roles could use Server-Side Request Forgery (SSRF) in report notifications to send system-authenticated requests to internal Splunk services, which could allow for changes to Search Head Cluster state and a denial of service. The vulnerability is possible because Splunk Secure Gateway does not validate report notification path values before it sends internal requests.