In Splunk Enterprise versions below 10.2.6, 10.0.9, and 9.4.14, an unauthenticated user could trick an authenticated user into running arbitrary Search Processing Language (SPL) commands using the permissions of the authenticated user through a crafted Splunk Web link. The SPL commands could access all relevant data. The vulnerability does not affect Splunk Enterprise 10.4 versions and above. The vulnerability is possible because Splunk Web substitutes form token values supplied through the Uniform Resource Locator (URL) into SPL searches without neutralizing them. The vulnerability requires the attacker to phish the user by tricking them into opening the crafted link. The unauthenticated user should not be able to exploit the vulnerability at will. For more information see Token reference (https://help.splunk.com/en/splunk-enterprise/create-dashboards-and-reports/simple-xml-dashboards/10.2/simple-xml-reference/token-reference) 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.