Remote Code Execution (RCE) through the REST API in Splunk Enterprise

In Splunk Enterprise versions below 10.4.2, a user with a high-privilege Splunk role that can manage search head clustering could use the search head cluster member bundle Representational State Transfer (REST) API to write files to locations that the user account running Splunk Enterprise can write to, which could allow for remote code execution. Successful exploitation could result in access to all relevant data and could affect the integrity and availability of the Splunk deployment. The vulnerability does not affect Splunk Enterprise versions below 10.4. The vulnerability is possible because the search head cluster member bundle REST API does not enforce the expected authorization boundary and does not validate bundle paths before accepting bundle content. For more information see Using the REST API reference (https://help.splunk.com/en/splunk-enterprise/rest-api-reference/10.2/introduction/using-the-rest-api-reference), About configuring role-based user access (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.2/manage-splunk-platform-users-and-roles/about-configuring-role-based-user-access), and About distributed search (https://help.splunk.com/en/splunk-enterprise/administer/distributed-search/9.4/overview-of-distributed-search/about-distributed-search) in the Splunk documentation.