CVE-2023-49923 in Enterprise Search
Summary
by MITRE • 12/12/2023
An issue was discovered by Elastic whereby the Documents API of App Search logged the raw contents of indexed documents at INFO log level. Depending on the contents of such documents, this could lead to the insertion of sensitive or private information in the App Search logs. Elastic has released 8.11.2 and 7.17.16 that resolves this issue by changing the log level at which these are logged to DEBUG, which is disabled by default.
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Analysis
by VulDB Data Team • 01/04/2024
The vulnerability identified as CVE-2023-49923 represents a significant logging security flaw within Elastic's App Search platform that has been classified under CWE-532 as "Information Exposure Through Log Data." This issue affects the Documents API component of App Search where raw document contents are being written to log files at the INFO level, which is typically enabled in production environments. The flaw stems from improper log level configuration where sensitive data should never be exposed through logging mechanisms regardless of the log level settings. The vulnerability impacts both version 7.17.16 and 8.11.2 of Elastic's App Search platform, indicating a widespread issue across the product's major release lines.
The technical implementation of this vulnerability occurs when the Documents API processes indexed documents and subsequently logs their raw contents without any sanitization or filtering mechanisms. This logging behavior exposes sensitive information that may include personally identifiable information, confidential business data, or proprietary content that should remain protected. The INFO log level is specifically chosen for this flaw because it is commonly enabled in production systems, making the exposure of sensitive data highly likely. The vulnerability's impact is amplified by the fact that log files are often retained for extended periods, creating persistent exposure windows for sensitive information. This type of flaw aligns with ATT&CK technique T1562.006 which covers "Impair Logs and Monitoring" and represents a classic case of insecure logging practices that violates fundamental security principles.
The operational impact of CVE-2023-49923 extends beyond simple information disclosure to encompass potential compliance violations and data breach risks. Organizations using Elastic App Search may unknowingly be exposing sensitive data through their logging infrastructure, particularly in regulated environments where data protection requirements such as gdpr, hipaa, or pci dss are applicable. The vulnerability creates a situation where sensitive documents can be inadvertently exposed to unauthorized individuals who have access to system logs, potentially including developers, system administrators, or other personnel who should not have access to such information. This exposure can lead to reputational damage, regulatory penalties, and legal consequences for organizations that fail to protect sensitive data adequately. The flaw also creates a scenario where attackers who gain access to log files could extract valuable intelligence from the indexed documents, making this vulnerability particularly dangerous in environments where the indexed data contains strategic business information or personal data.
The remediation implemented by Elastic addresses the core issue by changing the log level from INFO to DEBUG, which is disabled by default in production environments. This change aligns with security best practices outlined in the OWASP Logging Security Verification Standard, which emphasizes that sensitive data should never be logged at levels that are enabled in production systems. The fix demonstrates proper risk mitigation by ensuring that potentially sensitive information is only logged when explicit debugging is required, rather than being automatically included in regular operational logs. Organizations should immediately upgrade to versions 7.17.16 or 8.11.2 to resolve this vulnerability, and should also conduct thorough log reviews to identify any previously exposed sensitive information. The mitigation strategy also includes implementing log monitoring and access controls to ensure that logging configurations remain secure and that unauthorized individuals cannot access sensitive log data. This vulnerability serves as a reminder of the critical importance of log security practices and the potential for seemingly minor configuration issues to create significant security risks in enterprise environments.