CVE-2023-49923 is a medium-severity vulnerability identified in Elastic's Enterprise Search product, specifically affecting the Documents API of App Search in versions 7.0.0 and 8.0.0. The core issue involves the logging behavior of the Documents API, which was found to log the raw contents of indexed documents at the INFO log level. Since INFO is a commonly enabled log level in production environments, this behavior risks exposing sensitive or private information contained within those documents in the application logs. Such exposure could lead to confidentiality breaches if unauthorized users gain access to these logs. Elastic addressed this vulnerability by releasing patched versions 7.17.16 and 8.11.2, which change the logging level of document contents from INFO to DEBUG. DEBUG logging is typically disabled by default, thereby reducing the risk of inadvertent sensitive data exposure. The vulnerability is classified under CWE-532, which pertains to the insertion of sensitive information into log files. The CVSS v3.1 base score is 6.8, reflecting a medium severity level, with an attack vector of adjacent network (AV:A), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), and a scope change (S:C). The impact is high on confidentiality (C:H), with no impact on integrity or availability. No known exploits are currently reported in the wild. This vulnerability primarily concerns organizations that deploy Elastic Enterprise Search and use the App Search Documents API to index potentially sensitive data, as the logs could unintentionally expose such data to anyone with access to the log files or log management systems.

For European organizations, the exposure of sensitive data through logs can have significant regulatory and operational consequences. Given the strict data protection regulations under GDPR, inadvertent logging of personal data or confidential business information could lead to compliance violations, resulting in fines and reputational damage. Organizations in sectors such as finance, healthcare, legal, and government, which often handle sensitive personal or classified data, are particularly at risk. The vulnerability could allow attackers or unauthorized insiders who gain access to log files to harvest sensitive information without needing to compromise the primary data stores. This risk is exacerbated in multi-tenant or cloud environments where log access controls may be less stringent. Although exploitation requires some level of access to the network or system (adjacent network and low privileges), the lack of user interaction and the high confidentiality impact make this a notable risk. The vulnerability does not affect data integrity or availability, but the confidentiality breach alone is sufficient to cause serious harm, including data leaks and loss of trust.

European organizations should promptly upgrade to Elastic Enterprise Search versions 7.17.16 or 8.11.2 where this vulnerability is fixed. Until upgrades can be applied, organizations should audit and restrict access to log files containing App Search data, ensuring only authorized personnel have read permissions. Additionally, organizations should review and adjust logging configurations to disable INFO level logging of document contents or set the logging level to DEBUG only when necessary and in controlled environments. Implementing centralized log management with strict access controls and encryption at rest and in transit can further reduce exposure risks. It is also advisable to conduct regular log reviews to detect any inadvertent sensitive data exposure. Organizations should update their incident response and data protection policies to include monitoring for such logging issues and ensure compliance with GDPR requirements regarding data minimization and protection. Finally, educating developers and system administrators about secure logging practices will help prevent similar issues in the future.