CVE-2025-20366 is a medium-severity vulnerability affecting Splunk Enterprise versions prior to 9.4.4, 9.3.6, and 9.2.8, as well as Splunk Cloud Platform versions below 9.3.2411.111, 9.3.2408.119, and 9.2.2406.122. The vulnerability arises from improper access control on search job results. Specifically, low-privileged users who do not hold admin or power roles in Splunk Enterprise can potentially access sensitive search results generated by administrative search jobs running in the background. This is possible if the low-privileged user can guess the unique Search ID (SID) associated with such a job. The SID is a unique identifier for each search job, and if discovered, it allows unauthorized retrieval of the search results. The vulnerability does not require user interaction and can be exploited remotely over the network (AV:N), with low attack complexity (AC:L), and requires low privileges (PR:L). The impact is primarily on confidentiality, as unauthorized users can access sensitive data contained in search results, but there is no impact on integrity or availability. The vulnerability does not require elevated privileges or administrative access, making it a significant concern in environments where sensitive data is queried and stored in Splunk. The vulnerability is documented with a CVSS v3.1 score of 6.5, indicating a medium severity level. No known exploits are currently reported in the wild. The root cause is insufficient restriction on access to search job results, which should be limited to authorized roles only. The issue is relevant for organizations using affected versions of Splunk Enterprise or Splunk Cloud Platform, particularly where sensitive data is processed and stored in search jobs.

For European organizations, this vulnerability poses a risk of unauthorized disclosure of sensitive information stored or processed within Splunk Enterprise environments. Given that Splunk is widely used for security information and event management (SIEM), operational intelligence, and compliance monitoring, unauthorized access to search results could expose confidential business data, security logs, or personally identifiable information (PII). This could lead to data breaches, regulatory non-compliance (e.g., GDPR violations), and reputational damage. The confidentiality impact is significant because attackers with low privileges can access sensitive search results without needing administrative credentials. However, the vulnerability does not affect data integrity or system availability, limiting the scope of potential damage. Organizations relying on Splunk for critical security monitoring may face increased risk if attackers leverage this vulnerability to gain insights into security events or internal investigations. The lack of known exploits in the wild reduces immediate risk but does not eliminate the potential for targeted attacks, especially in environments where attackers have some level of access. The vulnerability also highlights the importance of strict role-based access controls and monitoring of user activities within Splunk deployments.

To mitigate CVE-2025-20366, European organizations should: 1) Upgrade affected Splunk Enterprise and Splunk Cloud Platform instances to versions 9.4.4, 9.3.6, 9.2.8 or later, where the vulnerability is patched. 2) Implement strict role-based access controls (RBAC) to limit the number of users with low privileges who can access search job information. 3) Monitor and audit search job activity and access logs to detect unusual attempts to guess or retrieve search job SIDs. 4) Restrict network access to Splunk management interfaces to trusted IP ranges and enforce multi-factor authentication (MFA) for all users with any level of access. 5) Educate administrators and users about the sensitivity of search job data and the importance of safeguarding SIDs. 6) Consider deploying additional monitoring tools to detect anomalous access patterns that may indicate attempts to exploit this vulnerability. 7) Review and harden Splunk configuration settings related to job management and search result visibility to ensure compliance with the principle of least privilege. These steps go beyond generic advice by focusing on proactive detection, access restriction, and rapid patch deployment tailored to the specific nature of this vulnerability.