In Splunk Enterprise versions below 8.1.13, 8.2.10, and 9.0.4, the ‘search_listener’ parameter in a search allows for a blind server-side request forgery (SSRF) by an authenticated user. The initiator of the request cannot see the response without the presence of an additional vulnerability within the environment.
https://research.splunk.com/application/ee69374a-d27e-4136-adac-956a96ff60fd