CVE-2025-20381 is a vulnerability identified in the Splunk MCP Server application, specifically in versions below 0.2.4. The vulnerability arises from an improper authorization check when users attempt to access resources or perform actions via the Model Context Protocol (MCP) tool named "run_splunk_query." Normally, the MCP tool enforces a strict allowlist of SPL (Search Processing Language) commands to prevent unauthorized queries. However, due to flawed validation, an attacker with access to this tool can embed SPL commands as sub-searches, effectively bypassing the allowlist controls. This bypass enables the execution of unauthorized SPL commands that could manipulate data, alter system behavior, or disrupt service availability beyond the intended scope of the MCP restrictions. The vulnerability requires the attacker to have privileges to use the "run_splunk_query" MCP tool but does not require additional user interaction, making it a network-exploitable issue with low attack complexity. The CVSS 3.1 base score is 5.4, reflecting medium severity, with the vector indicating network attack vector, low attack complexity, privileges required, no user interaction, unchanged scope, no confidentiality impact, but integrity and availability impacts. No public exploits are currently known, and no patches are linked in the provided data, but upgrading to version 0.2.4 or later is implied as the remediation. This vulnerability could allow attackers to perform unauthorized actions that compromise data integrity or availability within affected Splunk MCP Server environments.

For European organizations, the vulnerability poses a risk of unauthorized manipulation of Splunk queries, potentially leading to data integrity issues or denial of service conditions within Splunk MCP Server environments. Organizations relying on Splunk for security monitoring, operational intelligence, or compliance reporting could experience inaccurate analytics or disruptions in monitoring capabilities. This could delay incident detection or response, increasing exposure to other threats. The lack of confidentiality impact reduces the risk of data leakage but does not eliminate the risk of operational disruption. The requirement for privileges to access the MCP tool limits exploitation to insiders or attackers who have already gained some level of access, but the bypass of command restrictions elevates the risk of privilege escalation within the Splunk environment. European critical infrastructure sectors, financial institutions, and large enterprises using Splunk MCP Server could be particularly impacted due to their reliance on accurate and reliable data analytics.

1. Upgrade Splunk MCP Server to version 0.2.4 or later where the vulnerability is fixed. 2. Restrict access to the "run_splunk_query" MCP tool strictly to trusted and authorized personnel only, minimizing the number of users with such privileges. 3. Implement strict monitoring and logging of MCP tool usage to detect unusual or unauthorized query patterns that could indicate exploitation attempts. 4. Conduct regular audits of user privileges within Splunk environments to ensure least privilege principles are enforced. 5. Employ network segmentation and access controls to limit exposure of the MCP tool to only necessary network segments and users. 6. Develop incident response plans that include scenarios involving misuse of Splunk query capabilities to quickly contain and remediate potential exploitation. 7. Stay informed of vendor advisories and apply patches promptly once available if not already done.