CVE-2022-38149 in Consul Template
Summary
by MITRE • 08/17/2022
HashiCorp Consul Template through 0.29.1 inserts Sensitive Information into a Log File.
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Analysis
by VulDB Data Team • 08/17/2022
HashiCorp Consul Template version 0.29.1 contains a critical security flaw that allows sensitive information to be inadvertently written to log files during template processing operations. This vulnerability arises from improper handling of sensitive data within the template rendering system where confidential values such as API keys, passwords, or tokens are not adequately masked or sanitized before being logged. The flaw specifically manifests when Consul Template processes configurations that contain sensitive placeholders or variables that are subsequently rendered into log output without proper obfuscation mechanisms.
The technical implementation of this vulnerability stems from the template engine's logging functionality which does not distinguish between regular configuration data and sensitive credentials during the rendering process. When templates are evaluated, the system processes all variables and placeholders regardless of their sensitivity level, resulting in plaintext exposure of confidential information within log files that are typically accessible to system administrators and monitoring tools. This behavior violates fundamental security principles of information hiding and privilege separation, as it creates attack vectors where adversaries can gain access to sensitive credentials simply by examining log files. The vulnerability is categorized under CWE-532, which specifically addresses Information Exposure Through Log Files, and aligns with ATT&CK technique T1562.006 for Credential Access through log file exploitation.
The operational impact of this vulnerability is substantial as it directly compromises the security posture of systems relying on Consul Template for service discovery and configuration management. Attackers who gain access to log files can extract API tokens, database credentials, and other sensitive information that may have been used in the template processing context. This exposure can lead to unauthorized access to downstream services, data breaches, and lateral movement within network environments where Consul is deployed. The vulnerability affects organizations using Consul Template in production environments where log aggregation and monitoring systems are in place, potentially exposing credentials across multiple systems and services that depend on Consul for configuration management.
Organizations should immediately upgrade to Consul Template version 0.29.2 or later which includes proper sanitization of sensitive data in log output. Additionally, system administrators should implement log file access controls to limit who can read sensitive log entries and consider implementing log rotation with secure deletion policies. Security monitoring should include detection rules for sensitive information patterns in log files, and organizations should conduct regular audits of their logging configurations to ensure proper data sanitization. The fix implemented by HashiCorp addresses the root cause by introducing proper variable sanitization during template rendering and ensures that sensitive information is not written to log files unless explicitly configured to do so through secure mechanisms.