Ingest Actions UI in Splunk Enterprise 9.0.0 disabled TLS certificate validation

Description

When using Ingest Actions to configure a destination that resides on Amazon Simple Storage Service (S3) in Splunk Web, TLS certificate validation is not correctly performed and tested for the destination. The vulnerability only affects connections between Splunk Enterprise and an Ingest Actions Destination through Splunk Web and only applies to environments that have configured TLS certificate validation. It does not apply to Destinations configured directly in the outputs.conf configuration file. The vulnerability affects Splunk Enterprise version 9.0.0 and does not affect versions below 9.0.0, including the 8.1.x and 8.2.x versions. 

Solution

For Splunk Enterprise customers that use Ingest Actions, in particular to create or test new destinations, and have configured TLS certificate validation, upgrade Splunk Enterprise 9.0.0 to 9.0.1 or higher.

Product Status

Mitigations and Workarounds

In 9.0.0, you can enable TLS certification validation for previously created destinations by adding the following to the “[rfs:s3]” destination stanza in outputs.conf:

[rfs:s3]

# existing settings

remote.s3.sslVerifyServerCert=true

remote.s3.sslVerifyServerName=true

remote.s3.sslRootCaPath=<path to SSL CA cert chain>

This mirrors what was configured for enabling TLS certificate validation, but in the outputs.conf/[rfs:s3] stanza as opposed to server.conf/[sslConfig]. Restart Splunk Enterprise after making these changes.

Severity

If the environment has not configured a Destination in the Ingest Actions component via the user interface, there is no impact, and the vulnerability is Informational. If the environment has not configured TLS certificate validation, there is no impact and the vulnerability is Informational. If the environment has configured both, Splunk rates the severity as High, 7.4 with a CVSSv3.1 vector of CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Acknowledgments

Eric LaMothe at Splunk

Ali Mirheidari at Splunk