CVE-2025-20385 is a stored cross-site scripting (XSS) vulnerability affecting Splunk Enterprise versions below 10.0.2, 9.4.6, 9.3.8, and 9.2.10, as well as Splunk Cloud Platform versions below 10.1.2507.6, 10.0.2503.7, and 9.3.2411.117. The vulnerability arises because the software does not properly neutralize user-controllable input before embedding it into web pages served to other users. Specifically, a user with the 'admin_all_objects' capability can craft a malicious payload by injecting JavaScript code into the href attribute of an anchor tag within a navigation bar collection. When other users view the affected navigation bar, the injected script executes in their browsers, potentially leading to unauthorized actions such as session hijacking or data theft. However, exploitation requires the attacker to have high privileges and the victim to interact with the malicious content, which reduces the attack surface. The CVSS 3.1 base score is 2.4, reflecting low severity due to the limited impact on confidentiality, integrity, and availability, and the need for user interaction and elevated privileges. No known exploits have been reported in the wild, and no patches are linked in the provided data, though vendors typically release updates to address such issues.

For European organizations, the impact of CVE-2025-20385 is primarily related to potential unauthorized script execution in user browsers, which could lead to session hijacking, credential theft, or unauthorized actions within the Splunk interface. Given that exploitation requires a user with high privileges to inject the payload and other users to interact with it, the risk is mitigated by proper role management and user awareness. However, organizations with large Splunk deployments and multiple administrators could face internal threats if privileged accounts are compromised or misused. The vulnerability could also be leveraged in targeted attacks against critical infrastructure or sensitive data environments monitored via Splunk, potentially undermining trust in monitoring data integrity. The low CVSS score indicates limited direct impact on system availability or integrity, but the confidentiality of user sessions and data could be at risk if exploited.

European organizations should immediately verify their Splunk Enterprise and Cloud Platform versions and plan upgrades to the patched releases: 10.0.2, 9.4.6, 9.3.8, 9.2.10 for Enterprise and 10.1.2507.6, 10.0.2503.7, 9.3.2411.117 for Cloud. Until patches are applied, restrict the assignment of the 'admin_all_objects' role to only trusted personnel and enforce strict access controls and monitoring on privileged accounts. Implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. Educate users to be cautious when interacting with navigation elements, especially if unexpected behavior is observed. Regularly audit Splunk configurations and navigation collections for unauthorized modifications. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting the href attribute. Finally, monitor logs for unusual activity related to navigation bar changes or privilege escalations.