CVE-2025-20320 is a path traversal vulnerability affecting Splunk Enterprise versions prior to 9.4.3, 9.3.5, 9.2.7, and 9.1.10, as well as Splunk Cloud Platform versions below 9.3.2411.107, 9.3.2408.117, and 9.2.2406.121. The vulnerability arises because the software improperly sanitizes external input used to construct file pathnames within a restricted directory. Specifically, it fails to neutralize sequences like '.../...//' (doubled triple dot slash), which can resolve to locations outside the intended directory. This flaw can be exploited by a low-privileged user who does not have admin or power roles in Splunk. The attacker crafts a malicious payload via the User Interface - Views configuration page. However, exploitation requires social engineering: the attacker must trick an administrator-level user into initiating a request in their browser, effectively combining a path traversal with a cross-user interaction. Successful exploitation can lead to deletion of arbitrary files within the Splunk directory, resulting in a denial of service (DoS) condition. The vulnerability does not impact confidentiality but affects integrity and availability due to potential file deletions. The CVSS v3.1 base score is 6.3 (medium severity), reflecting network attack vector, low attack complexity, low privileges required, user interaction needed, unchanged scope, no confidentiality impact, limited integrity impact, and high availability impact. No known exploits are reported in the wild yet. The vulnerability is significant because Splunk Enterprise is widely used for security information and event management (SIEM), log aggregation, and operational intelligence, making availability critical for security monitoring and incident response. The attack vector involves a low-privileged user leveraging a browser-based request initiated by an admin, which complicates direct exploitation but does not eliminate risk, especially in environments with many users and complex role assignments.

For European organizations, this vulnerability poses a risk to the availability and integrity of their Splunk Enterprise deployments, which are often central to security monitoring and compliance operations. A successful DoS could disrupt log collection, alerting, and forensic capabilities, potentially delaying detection and response to other security incidents. This disruption could have regulatory implications under GDPR and other data protection laws if it impairs incident response or audit trails. The requirement for phishing an administrator user means that organizations with strong user awareness and phishing defenses may reduce risk, but insider threats or targeted social engineering campaigns could still succeed. The ability to delete arbitrary files within the Splunk directory could also lead to partial data loss or corruption of critical configuration files, impacting operational continuity. Given Splunk’s role in many critical infrastructure and enterprise environments, the impact could extend to sectors such as finance, healthcare, energy, and government within Europe, where continuous monitoring is essential for compliance and security.

1. Immediate patching: Upgrade Splunk Enterprise and Splunk Cloud Platform to the fixed versions (9.4.3, 9.3.5, 9.2.7, 9.1.10 or later) as soon as possible to eliminate the vulnerability. 2. Role and privilege review: Audit and minimize the number of users with admin or power roles to reduce the attack surface. 3. User interface restrictions: Limit access to the User Interface - Views configuration page to trusted users only. 4. Phishing defenses: Enhance phishing awareness training for administrators and implement technical controls such as email filtering, multi-factor authentication (MFA), and browser security policies to reduce the likelihood of successful social engineering. 5. Monitoring and alerting: Implement monitoring for unusual file deletion or modification activities within Splunk directories and alert on suspicious behavior. 6. Network segmentation: Restrict network access to Splunk management interfaces to trusted networks and users. 7. Incident response readiness: Prepare response plans for potential DoS incidents affecting Splunk to minimize downtime and data loss. 8. Backup and recovery: Ensure regular backups of Splunk configuration and data directories to enable rapid restoration in case of file deletion or corruption.