Splunk Enterprise lacked TLS certificate validation for Splunk-to-Splunk communication by default

Description

Splunk Enterprise peers in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203 did not validate the TLS certificates during Splunk-to-Splunk communications by default. Splunk peer communications configured properly with valid certificates were not vulnerable. However, an administrator could add a peer without a valid certificate and connections from misconfigured nodes without valid certificates did not fail by default. 

For Splunk Enterprise, update to Splunk Enterprise version 9.0 or higher and Configure TLS host validation for Splunk-to-Splunk communications to enable the remediation.

At the time of publishing, we have no evidence of exploitation of this vulnerability by external parties.

Solution

For Splunk Enterprise, upgrade to version 9.0 or higher and Configure TLS validation for Splunk-to-Splunk communications.

For Splunk Cloud Platform customers, Splunk is actively patching and monitoring Splunk Cloud instances.

Product Status

Severity Considerations

Splunk strongly recommends securing your Splunk environment with hardened TLS configurations. See Securing the Splunk platform with TLS for more information. However, the vulnerability assumes that you have configured your Splunk platform instances to use transport layer security (TLS) certificates for secure network connections. If you have not and are using the default certificates, the vulnerability is not applicable and is informational.

Acknowledgments

Chris Green at Splunk

Changelog

2022-07-18: Added Severity Considerations