CVE-2023-46675: Elastic Kibana Information Disclosure Flaw

CVE-2023-46675 Overview

CVE-2023-46675 is an information disclosure vulnerability discovered by Elastic in Kibana, their popular data visualization and exploration platform for Elasticsearch. The vulnerability allows sensitive information to be inadvertently recorded in Kibana logs under specific conditions—either when an error occurs during communication with Elasticsearch or when debug-level logging is enabled.

Critical Impact

Sensitive credentials including kibana_system account credentials, API keys, end-user credentials, private keys, bearer tokens, session tokens for third-party integrations, authorization headers, client secrets, and local file paths may be exposed in log files.

Affected Products

• Elastic Kibana versions prior to 8.11.2
• Elastic Kibana versions prior to 7.17.16

Discovery Timeline

• December 13, 2023 - CVE-2023-46675 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2023-46675

Vulnerability Analysis

This vulnerability is classified under CWE-532 (Insertion of Sensitive Information into Log File). The flaw exists in Kibana's error handling and logging mechanisms, which can inadvertently capture and store sensitive authentication data in plain text log files.

The exposure of sensitive data occurs in two primary scenarios. First, when Kibana encounters an unexpected error while communicating with Elasticsearch, the error handling routines may capture and log request/response data that includes authentication credentials. Second, when administrators enable debug-level logging for troubleshooting purposes, verbose logging captures detailed information about requests and internal operations, including sensitive authentication headers and credentials.

The vulnerability is particularly concerning because log files are often retained for extended periods, backed up to multiple locations, and may be accessible to personnel who should not have access to production credentials. Additionally, this vulnerability is notable as it represents an incomplete fix for a previous similar issue (ESA-2023-25) that was addressed in Kibana 8.11.1.

Root Cause

The root cause of this vulnerability lies in insufficient sanitization of log output in Kibana's error handling and debug logging code paths. When constructing log messages during error conditions or debug operations, the application fails to properly redact or exclude sensitive fields from request contexts, error objects, and internal state information. This oversight allows credentials, tokens, and other sensitive data to be written to log files in cleartext.

Attack Vector

The attack vector requires network access with low-privileged authentication to the affected Kibana instance. An attacker could exploit this vulnerability by:

1. Gaining access to Kibana log files through misconfigured file permissions, log aggregation systems, or backup repositories
2. Triggering error conditions that cause sensitive information to be logged
3. Waiting for administrators to enable debug logging during troubleshooting activities

Once sensitive data is captured in logs, an attacker with read access to those log files can extract credentials for the kibana_system user, API keys, end-user session tokens, and other authentication material. These credentials could then be used to escalate privileges, access protected data, or impersonate legitimate users.

Detection Methods for CVE-2023-46675

Indicators of Compromise

• Presence of credential patterns (API keys, bearer tokens, passwords) in Kibana log files
• Unusual access patterns to Kibana log directories or log aggregation systems
• Evidence of log file exfiltration or unauthorized log access

Detection Strategies

• Implement log file integrity monitoring to detect unauthorized access or modifications
• Deploy data loss prevention (DLP) tools to scan log files for credential patterns
• Monitor for unusual file access to Kibana log directories using file integrity monitoring solutions
• Review access controls on log aggregation systems for unauthorized queries

Monitoring Recommendations

• Configure alerts for access to Kibana log files from unexpected sources or user accounts
• Implement automated scanning of log files for sensitive data patterns before archival
• Monitor Kibana configuration changes, particularly changes to logging levels
• Set up alerting for debug logging being enabled in production environments

How to Mitigate CVE-2023-46675

Immediate Actions Required

• Upgrade to Kibana 8.11.2 or 7.17.16 or later immediately
• Review existing Kibana log files for exposed credentials and rotate any potentially compromised secrets
• Ensure debug logging is disabled in production environments
• Restrict access to Kibana log files to only essential personnel

Patch Information

Elastic has released security updates to address this vulnerability. Organizations should upgrade to the following patched versions:

• Kibana 8.x series: Upgrade to version 8.11.2 or later
• Kibana 7.x series: Upgrade to version 7.17.16 or later

For detailed patch information, refer to the Elastic Security Update ESA-2023-27.

Workarounds

• Disable debug-level logging in production Kibana instances until patches can be applied
• Implement strict file system permissions on Kibana log directories to limit access
• Configure log rotation with secure deletion to minimize the window of exposure
• Consider implementing a log sanitization layer that removes sensitive patterns before storage

# Verify current Kibana logging level and restrict log file permissions
# Check Kibana configuration for debug logging
grep -r "logging.root.level" /etc/kibana/kibana.yml

# Restrict access to Kibana log directory
chmod 750 /var/log/kibana
chown kibana:kibana /var/log/kibana

# Ensure debug logging is disabled (set to info or warn)
# In kibana.yml, verify or set:
# logging.root.level: info