Risky command safeguards bypass via 'rex' search command field names in Splunk Enterprise

Description

In Splunk Enterprise versions below 8.2.9 and 8.1.12, the way that the ‘rex’ search command handles field names lets an attacker bypass SPL safeguards for risky commands. The vulnerability requires the attacker to phish the victim by tricking them into initiating a request within their browser. The attacker cannot exploit the vulnerability at will.

Solution

For Splunk Enterprise, upgrade versions to 8.1.12, 8.2.9, or higher.

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

Product Status

Mitigations and Workarounds

The vulnerability affects instances with Splunk Web enabled, disabling Splunk Web is a possible workaround. See Disable unnecessary Splunk Enterprise components and the web.conf configuration specification file for more information on disabling Splunk Web.

Detections

None

Severity

Splunk rates the vulnerability as High, 8.1, with a CVSS Vectors of CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N. The vulnerability requires a user interaction within a browser of a privileged user. The vulnerability lets an attacker run risky commands with permissions of a user who holds the “power” Splunk role. For more information on risky commands and potential impacts, see SPL safeguards for risky commands.

If the Splunk Enterprise instance does not run Splunk Web, there is no impact and the severity is Informational.

Acknowledgments

Cuong Dong at Splunk

Changelog

2022-11-11: Added “Coung Dong” to the Acknowledgements section