Splunk XSS Privilege Escalation via Custom URLs in Dashboard (CVE-2024-36992)

A critical cross-site scripting (XSS) vulnerability, identified as CVE-2024-36992, affects Splunk Enterprise and Splunk Cloud Platform. This flaw allows attackers to achieve privilege escalation by exploiting custom URLs within Splunk dashboards. Malicious POST requests targeting the splunk_internal_metrics/data/ui/views endpoint can inject and execute arbitrary JavaScript. Upon execution, typically when a privileged user views the compromised dashboard, the XSS payload facilitates the creation of new user accounts with elevated access permissions on the Splunk server. This vulnerability presents a significant risk, enabling unauthorized administrative control and potential data exfiltration or manipulation within the Splunk environment. Defenders should prioritize patching and monitoring for the specific POST requests and subsequent user creation events.

Attack Chain

1. Initial Access / Vulnerability Exploitation (T1189): An attacker, potentially with low-privileged access, injects malicious JavaScript into a custom URL field within a Splunk dashboard, exploiting the CVE-2024-36992 XSS vulnerability.
2. Payload Delivery (T1059.004): The crafted XSS payload is delivered via a POST request to the internal Splunk endpoint /splunk_internal_metrics/data/ui/views, embedding the malicious script within the dashboard configuration.
3. Triggering (T1203): A privileged Splunk user (e.g., an administrator) accesses or views the compromised dashboard containing the malicious custom URL.
4. Client-Side Execution (T1059.004): The embedded JavaScript executes in the context of the privileged user's browser, leveraging their authenticated session within the Splunk interface.
5. Privilege Escalation Action (T1068 / T1098): The executed script issues commands to the Splunk API, such as audittrail actions, to create a new user account with administrative or other high-level privileges.
6. Persistence / Unauthorized Account Creation (T1136.001): A new user account with elevated permissions is successfully created on the Splunk server, granting the attacker persistent access and control.
7. Post-Exploitation (TA0011): The attacker utilizes the newly created privileged account to perform further malicious activities, including data exfiltration, system configuration changes, or deployment of additional implants.

Impact

The successful exploitation of CVE-2024-36992 leads directly to privilege escalation within the Splunk environment. This enables unauthorized attackers to create new user accounts with administrative or other high-level privileges, effectively gaining full control over the Splunk instance. Such compromise can result in sensitive data exfiltration, manipulation of critical log data, disruption of Splunk services, or the use of the Splunk server as a pivot point for further attacks against integrated systems. While the number of victims is not specified, all organizations utilizing affected versions of Splunk Enterprise and Splunk Cloud Platform are at risk of severe data integrity and confidentiality breaches.

Recommendation

• Patch CVE-2024-36992 immediately by applying the latest security updates provided by Splunk, available through the official advisory at https://advisory.splunk.com/.
• Deploy the provided Sigma rule "Detect POST Requests to Splunk UI View Endpoint (CVE-2024-36992)" to identify suspicious activity targeting the splunk_internal_metrics/data/ui/views endpoint.
• Deploy the provided Sigma rule "Detect High-Privilege Splunk User Creation (CVE-2024-36992 Context)" to monitor for unauthorized administrative user account creation.
• Ensure full logging is enabled for Splunk's internal indexes, specifically _audit and _internal, as these are critical log sources for detecting this threat.