Missing Authorization through REST API Endpoints in Splunk Secure Gateway

In Splunk Enterprise versions below 10.4.4, 10.2.8, 10.0.11, and 9.4.16, and Splunk Secure Gateway versions below 3.10.12, 3.9.26, and 3.8.73, a low-privileged user that does not hold the "admin" Splunk role or the "sc_admin" Splunk Secure Gateway role could read mobile alert notification data for other users through Splunk Secure Gateway App Key Value Store (KV Store) Representational State Transfer (REST) API endpoints.
The vulnerability is possible because the affected Splunk Secure Gateway App Key Value Store collections do not enforce user-level authorization for read requests.
For more information see About the app key value store (https://help.splunk.com/en/splunk-enterprise/administer/admin-manual/10.2/administer-the-app-key-value-store/about-the-app-key-value-store) and About configuring role-based user access (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.2/manage-splunk-platform-users-and-roles/about-configuring-role-based-user-access) in the Splunk documentation.