In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, a user who does not hold the "admin" or "power" Splunk roles could affect system integrity and availability by sending a crafted Representational State Transfer (REST) API request that deletes or temporarily overwrites files writable by the user account running Splunk Enterprise processes on a non-captain search head cluster member. The vulnerability is possible because Search Head Clustering bundle replication does not validate the name of a replicated bundle file or neutralize NUL bytes before constructing the member bundle path. For more information see About search head clustering (https://help.splunk.com/en/splunk-enterprise/administer/distributed-search/10.4/overview-of-search-head-clustering/about-search-head-clustering), 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 Secure Splunk Enterprise service accounts (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/9.0/install-splunk-enterprise-securely/secure-splunk-enterprise-service-accounts) in the Splunk documentation.
Upgrade Splunk Enterprise to versions 10.4.2, 10.2.6, 10.0.9, and 9.4.14, or higher.