CVE-2025-20373 affects the Splunk Add-on for Palo Alto Networks versions below 2.0.2, where sensitive client secrets are inadvertently logged in plaintext within the _internal index during the configuration of new Data Security Accounts. This vulnerability arises because the add-on writes these secrets directly to log files accessible via the internal Splunk index, which is by default only accessible to users with administrative privileges. An attacker with local access to the system or administrative access to the internal index could extract these secrets, potentially enabling unauthorized access to Palo Alto Networks data or systems. However, exploitation requires either local system access or elevated Splunk privileges, which limits the attack surface. The vulnerability does not affect data integrity or system availability, and no user interaction is required. The CVSS 3.1 score of 2.7 (low) reflects the limited confidentiality impact and high privilege requirement. No known exploits are currently reported in the wild. The vulnerability highlights the importance of secure logging practices and strict role-based access controls within Splunk environments, especially when handling sensitive credentials.

For European organizations, this vulnerability poses a risk primarily to confidentiality if an attacker gains administrative access to Splunk internal indexes or local system access. Exposure of client secrets could lead to unauthorized access to Palo Alto Networks integrations or data, potentially facilitating further compromise or data exfiltration. Organizations relying heavily on Splunk for security monitoring and Palo Alto Networks for network security may face increased risk if internal access controls are lax. Critical infrastructure sectors such as finance, energy, and government agencies in Europe, which often deploy these technologies, could be targeted for espionage or disruption. However, the requirement for high privileges and no direct impact on integrity or availability reduces the overall threat level. Still, the presence of sensitive credentials in logs represents a compliance and operational risk, especially under GDPR and other data protection regulations prevalent in Europe.

European organizations should immediately review and restrict access to the Splunk internal index, ensuring only trusted administrator-level roles have access. Implement strict role-based access controls and audit logs for any access to internal indexes. Upgrade the Splunk Add-on for Palo Alto Networks to version 2.0.2 or later, where this logging issue is resolved. Avoid storing sensitive credentials in logs or plaintext files and consider encrypting any necessary sensitive data within logs. Regularly review Splunk configurations and user roles to minimize privilege creep. Employ network segmentation and host-based controls to limit local access to Splunk servers. Additionally, monitor for unusual access patterns to internal indexes and conduct periodic security assessments of Splunk deployments. Incorporate these controls into compliance frameworks to ensure adherence to European data protection standards.