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 https://docs.splunk.com/Documentation/SplunkCloud/latest/Security/SPLsafeguards . 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.
In Splunk Enterprise versions below 8.1.12, 8.2.9, and 9.0.2, a remote user who can create search macros and schedule search reports can cause a denial of service through the use of specially crafted search macros.
In Splunk Enterprise versions below 8.2.9, 8.1.12, and 9.0.2, an authenticated user can execute arbitrary code through the dashboard PDF generation component.
In Splunk Enterprise versions below 8.1.12, 8.2.9, and 9.0.2, a remote user that holds the “power” Splunk role can store arbitrary scripts that can lead to persistent cross-site scripting (XSS). The vulnerability affects instances with Splunk Web enabled.
In Splunk Enterprise versions in the following table, an authenticated user can craft a dashboard that could potentially leak information (for example, username, email, and real name) about Splunk users, when visited by another user through the drilldown component. The vulnerability requires user access to create and share dashboards using Splunk Web.
In Splunk Enterprise and Universal Forwarder versions in the following table, indexing a specially crafted ZIP file using the file monitoring input can result in a crash of the application. Attempts to restart the application would result in a crash and would require manually removing the malformed file.
Dashboards in Splunk Enterprise versions before 9.0 might let an attacker inject risky search commands into a form token when the token is used in a query in a cross-origin request. The result bypasses SPL safeguards for risky commands. See New capabilities can limit access to some custom and potentially risky commands (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/SPLsafeguards#New_capabilities_can_limit_access_to_some_custom_and_potentially_risky_commands) for more information. Note that the attack is browser-based and an attacker cannot exploit it at will.
In universal forwarder versions before 9.0, management services are available remotely by default. When not required, it introduces a potential exposure, but it is not a vulnerability. If exposed, we recommend each customer assess the potential severity specific to your environment. In 9.0, the universal forwarder now binds the management port to localhost preventing remote logins by default. If management services are not required in versions before 9.0, set disableDefaultPort = true in server.conf OR allowRemoteLogin = never in server.conf OR mgmtHostPort = localhost in web.conf. See Configure universal forwarder management security (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation#Configure_universal_forwarder_management_security) for more information on disabling the remote management services.
In Splunk Enterprise and Universal Forwarder versions before 9.0, the Splunk command-line interface (CLI) did not validate TLS certificates while connecting to a remote Splunk platform instance by default. After updating to version 9.0, see Configure TLS host name validation for the Splunk CLI https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation#Configure_TLS_host_name_validation_for_the_Splunk_CLI to enable the remediation. The vulnerability does not affect the Splunk Cloud Platform. At the time of publishing, we have no evidence of exploitation of this vulnerability by external parties.
The issue requires conditions beyond the control of a potential bad actor such as a machine-in-the-middle attack. Hence, Splunk rates the complexity of the attack as High.
Splunk Enterprise deployment servers in versions before 9.0 allow unauthenticated downloading of forwarder bundles. Remediation requires you to update the deployment server to version 9.0 and Configure authentication for deployment servers and clients (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/ConfigDSDCAuthEnhancements#Configure_authentication_for_deployment_servers_and_clients). Once enabled, deployment servers can manage only Universal Forwarder versions 9.0 and higher. Though the vulnerability does not directly affect Universal Forwarders, remediation requires updating all Universal Forwarders that the deployment server manages to version 9.0 or higher prior to enabling the remediation.