A significant security flaw has been identified in Splunk Enterprise, a widely used platform for searching, monitoring, and analyzing machine-generated data. This vulnerability, designated as CVE-2025-20297, enables attackers with minimal privileges to execute unauthorized JavaScript code through a reflected Cross-Site Scripting (XSS) exploit.
Understanding the Vulnerability
The flaw resides in the dashboard PDF generation component of Splunk Enterprise, specifically within the `pdfgen/render` REST endpoint. By exploiting this vulnerability, attackers can craft malicious payloads that, when processed by the system, execute arbitrary JavaScript code in the browsers of unsuspecting users. This type of attack is particularly concerning because it can be initiated by users with low-level privileges, excluding those with admin or power roles. Consequently, even standard users with limited access can potentially compromise the sessions of other users.
Technical Details
The vulnerability is classified under CWE-79 (Cross-Site Scripting) and has been assigned a CVSSv3.1 score of 4.3, indicating a medium-severity risk. The CVSSv3.1 vector string is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, which translates to:
– Attack Vector (AV): Network
– Attack Complexity (AC): Low
– Privileges Required (PR): Low
– User Interaction (UI): None
– Scope (S): Unchanged
– Confidentiality Impact (C): Low
– Integrity Impact (I): None
– Availability Impact (A): None
This vector indicates that the attack can be executed remotely with low complexity, requires low privileges, and does not necessitate user interaction.
Affected Versions
The vulnerability impacts a broad range of Splunk products across multiple version branches:
– Splunk Enterprise:
– All releases below 9.4.2, 9.3.4, and 9.2.6.
– Specifically, the Splunk Web component in versions 9.4.1, 9.3.0 through 9.3.3, and 9.2.0 through 9.2.5.
– Notably, Splunk Enterprise 9.1 versions remain unaffected.
– Splunk Cloud Platform:
– Versions below 9.3.2411.102, 9.3.2408.111, and 9.2.2406.118.
It’s important to note that the vulnerability specifically affects instances with Splunk Web enabled, as this component handles the PDF generation functionality where the XSS flaw exists.
Discovery and Reporting
The vulnerability was discovered by Klevis Luli from Splunk’s security team. Upon identification, Splunk promptly issued security updates and advisories to mitigate the risk associated with this flaw.
Mitigation Strategies
To address this vulnerability, Splunk strongly recommends the following actions:
1. Upgrade to Patched Versions:
– For Splunk Enterprise users, upgrade to versions 9.4.2, 9.3.4, 9.2.6, or higher.
– Splunk is actively monitoring and automatically patching affected Splunk Cloud Platform instances to ensure customer security.
2. Disable Splunk Web:
– As an interim workaround, organizations can disable Splunk Web functionality entirely. This action effectively eliminates the attack vector since the vulnerability specifically targets the web interface’s PDF generation component. However, this mitigation may significantly impact user experience and dashboard functionality.
Recommendations for Security Teams
Given the potential for session hijacking and unauthorized code execution, security teams should prioritize the following actions:
– Immediate Updates: Ensure that all Splunk Enterprise instances are updated to the latest patched versions as recommended.
– Review User Privileges: Assess and adjust user privilege assignments to minimize the risk posed by low-privileged users.
– Monitor for Exploitation Attempts: Implement monitoring mechanisms to detect any attempts to exploit this vulnerability.
– Educate Users: Inform users about the potential risks and encourage them to report any suspicious activities.
Conclusion
The discovery of CVE-2025-20297 underscores the importance of proactive security measures and timely updates. Organizations utilizing Splunk Enterprise should act swiftly to apply the recommended patches and consider interim workarounds to mitigate the risk associated with this vulnerability. By staying vigilant and adhering to best practices, organizations can protect their systems and data from potential exploitation.
