Exposure of Sensitive Information to an Unauthorized Actor through the REST API in Splunk Enterprise

In Splunk Enterprise 10.4 versions below 10.4.2, an unauthenticated user could read Prometheus service metrics from the Edge Processor SPL2 Preview sidecar, including service details that expose relevant runtime and build metadata for the sidecar. The vulnerability does not affect Splunk Enterprise versions below 10.4. The information disclosure is possible because the Prometheus metrics endpoint in the Edge Processor SPL2 Preview sidecar lacks authentication, which lets any client that can reach the sidecar retrieve the metrics without credentials. For more information see About Splunk sidecars (https://help.splunk.com/en/splunk-enterprise/administer/admin-manual/10.4/splunk-sidecars/about-splunk-sidecars) in the Splunk documentation.