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.

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 attacker with administrator credentials 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 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

The httplib and urllib Python libraries that Splunk shipped with Splunk Enterprise did not validate certificates using the certificate authority (CA) certificate stores by default in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203. Python 3 client libraries now verify server certificates by default and use the appropriate CA certificate stores for each library. Apps and add-ons that include their own HTTP libraries are not affected. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

Splunk Enterprise deployment servers in versions before 8.1.10.1, 8.2.6.1, and 9.0 let clients deploy forwarder bundles to other deployment clients through the deployment server. An attacker that compromised a Universal Forwarder endpoint could use the vulnerability to execute arbitrary code on all other Universal Forwarder endpoints subscribed to the deployment server.

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.

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 attacker with administrator credentials 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 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

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.

The Monitoring Console app configured in Distributed mode allows for a Reflected XSS in a query parameter in Splunk Enterprise versions before 8.1.4. The Monitoring Console app is a bundled app included in Splunk Enterprise, not for download on SplunkBase, and not installed on Splunk Cloud Platform instances. Note that the Cloud Monitoring Console is not impacted.

In Splunk Enterprise versions before 8.1.2, the uri path to load a relative resource within a web page is vulnerable to path traversal. It allows an attacker to potentially inject arbitrary content into the web page (e.g., HTML Injection, XSS) or bypass SPL safeguards for risky commands. The attack is browser-based. An attacker cannot exploit the attack at will and requires the attacker to initiate a request within the victim's browser (e.g., phishing).

When handling a mismatched pre-authentication cookie, the application leaks the internal error message in the response, which contains the Splunk Enterprise local system path. The vulnerability impacts Splunk Enterprise versions before 8.1.0.