Improper Input Validation through the collect Command in Splunk Enterprise

In Splunk Enterprise versions below 10.4.3, 10.2.7, 10.0.10, and 9.4.15, a user that holds a role with the run_collect capability could use the collect Search Processing Language (SPL) command to add attacker-controlled content to system-level messages on the Splunk platform instance. The vulnerability is possible because the collect command does not validate the index name before processing the value. For more information see collect (https://help.splunk.com/en/splunk-enterprise/search/spl-search-reference/10.4/search-commands/collect), Define roles on the Splunk platform with capabilities (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.4/manage-splunk-platform-users-and-roles/define-roles-on-the-splunk-platform-with-capabilities), and System endpoint descriptions (https://help.splunk.com/en/splunk-enterprise/rest-api-reference/10.4/system-endpoints/system-endpoint-descriptions) in the Splunk documentation.