CVE-2024-29945 is a vulnerability identified in Splunk Enterprise versions below 9.2.1, 9.1.4, and 9.0.9, where sensitive authentication tokens can be inadvertently written to log files. This occurs specifically when Splunk is operated in debug mode or when the JsonWebToken component's logging level is set to DEBUG, causing detailed token validation information to be logged. These logs may contain authentication tokens that, if accessed by an attacker, could be used to impersonate legitimate users or escalate privileges within the Splunk environment. The vulnerability is network exploitable with low complexity but requires the attacker to have high privileges (PR:H) on the system, though no user interaction is needed. The impact affects confidentiality, integrity, and availability, as exposure of tokens can lead to unauthorized access and potential manipulation or disruption of security monitoring data. Although no exploits have been reported in the wild yet, the vulnerability's nature and the critical role of Splunk in enterprise security monitoring make it a significant risk. The vulnerability was publicly disclosed on March 27, 2024, with a CVSS v3.1 score of 7.2, categorized as high severity. The issue underscores the risks of verbose logging in production environments, especially for security-sensitive components like authentication token handling. The recommended remediation is to upgrade to patched versions of Splunk Enterprise and to avoid enabling debug-level logging for JsonWebToken components unless absolutely necessary and in controlled environments.

For European organizations, the exposure of authentication tokens in Splunk logs can lead to severe security breaches. Attackers gaining access to these tokens could impersonate users or administrators, leading to unauthorized access to sensitive data, manipulation of security logs, and potential disruption of incident detection and response capabilities. This undermines the confidentiality and integrity of security monitoring data, which is critical for compliance with regulations such as GDPR and NIS Directive. The availability of Splunk services could also be impacted if attackers leverage the tokens to disrupt or disable logging and monitoring functions. Organizations in sectors with high regulatory scrutiny and critical infrastructure, such as finance, energy, and telecommunications, face heightened risks. The requirement for high privileges to exploit the vulnerability means insider threats or attackers who have already compromised lower-level access could escalate their control. The lack of known exploits in the wild currently reduces immediate risk but does not diminish the urgency for mitigation given the potential impact.

1. Upgrade Splunk Enterprise to versions 9.2.1, 9.1.4, 9.0.9 or later where this vulnerability is patched. 2. Immediately audit and disable debug mode in production environments unless strictly necessary for troubleshooting. 3. Review and adjust logging configurations to ensure the JsonWebToken component is not set to DEBUG logging level in production. 4. Implement strict access controls and monitoring on log files to prevent unauthorized access, including encryption of logs at rest and in transit. 5. Conduct regular audits of logging practices and token handling to detect any inadvertent exposure. 6. Use Splunk’s role-based access controls to limit who can change logging levels or access sensitive logs. 7. Educate administrators about the risks of verbose logging and enforce policies to restrict debug logging to secure, isolated environments. 8. Monitor for unusual access patterns to logs and authentication tokens that could indicate exploitation attempts. 9. Integrate vulnerability management processes to ensure timely application of security patches.