In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, an unauthenticated user could cause an authenticated user to run arbitrary Search Processing Language (SPL) searches on their behalf through the Event Type Builder. This could expose all relevant data and stored credentials. The vulnerability is possible when the Event Type Builder accepts cross-site request input and retains SPL-affecting values while building sample event searches. The vulnerability requires the attacker to phish the affected user by tricking them into initiating a request within their browser. The unauthenticated user should not be able to exploit the vulnerability at will. For more information see Automatically find and build event types (https://help.splunk.com/en/splunk-enterprise/manage-knowledge-objects/knowledge-management-manual/9.0/event-types/automatically-find-and-build-event-types) in the Splunk documentation.
The vulnerability affects instances with Splunk Web turned on. Turning Splunk Web off is a possible workaround. See Disable unnecessary Splunk Enterprise components and the web.conf configuration specification file for more information on turning off Splunk Web.
Upgrade Splunk Enterprise to versions 10.4.2, 10.2.6, 10.0.9, and 9.4.14, or higher.