CVE-2019-7612 in Logstash
Summary
by MITRE
A sensitive data disclosure flaw was found in the way Logstash versions before 5.6.15 and 6.6.1 logs malformed URLs. If a malformed URL is specified as part of the Logstash configuration, the credentials for the URL could be inadvertently logged as part of the error message.
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Analysis
by VulDB Data Team • 08/07/2023
The vulnerability identified as CVE-2019-7612 represents a critical sensitive data disclosure issue within the Logstash logging platform that affected versions prior to 5.6.15 and 6.6.1. This flaw stems from improper handling of malformed URLs during the logging process, creating an unintended exposure of authentication credentials that could compromise system security. The vulnerability specifically manifests when Logstash encounters malformed URLs in its configuration, leading to error messages that inadvertently include credential information from the problematic URLs.
The technical root cause of this vulnerability lies in the insufficient sanitization of URL components within Logstash's error logging mechanism. When Logstash processes configuration files containing malformed URLs, the system generates error messages that contain the complete URL structure including username and password parameters. This occurs because the logging subsystem does not properly filter or redact credential information from URLs before incorporating them into error output. The flaw operates at the application level and demonstrates poor input validation practices, aligning with CWE-200 which addresses improper handling of sensitive information and CWE-532 which covers information exposure through log files. The vulnerability creates a pathway for attackers to extract authentication credentials through routine error logging operations that occur during system operation.
The operational impact of CVE-2019-7612 extends beyond simple credential exposure, as it can facilitate broader security compromise within environments utilizing vulnerable Logstash versions. Attackers who gain access to log files containing these error messages can extract username and password combinations, potentially enabling them to access other systems or services that share the same credentials. This risk is particularly elevated in environments where Logstash processes configuration data from untrusted sources or where multiple services rely on the same authentication credentials. The vulnerability's exploitation requires minimal technical skill and can occur during normal system operation, making it particularly dangerous as it may go undetected for extended periods. Organizations using Logstash for centralized logging across distributed systems face increased risk of credential compromise, especially when logs are stored in accessible locations or when log aggregation systems lack proper access controls. This vulnerability directly impacts the principle of least privilege and can lead to privilege escalation attacks when compromised credentials are used against other system components.
Mitigation strategies for CVE-2019-7612 focus primarily on upgrading to patched versions of Logstash where the vulnerability has been addressed through proper URL sanitization and credential handling. Organizations should immediately implement version updates to Logstash 5.6.15 or 6.6.1, which contain the necessary fixes to prevent credential exposure in error messages. Additionally, system administrators should review and implement proper log filtering mechanisms that remove or redact URL components from log entries before they are stored or transmitted. The implementation of centralized log management solutions with access controls and regular log auditing can help detect and prevent unauthorized access to potentially compromised credential information. Security teams should also establish monitoring procedures to identify unusual patterns in error logging that might indicate credential exposure, and consider implementing log rotation policies that limit the retention period of sensitive information. Organizations utilizing vulnerable versions should conduct comprehensive security assessments to identify any exposed credentials and implement immediate credential rotation procedures. This vulnerability highlights the importance of following security best practices including proper input validation, secure coding practices, and regular security updates as outlined in various security frameworks and standards including those referenced in the ATT&CK framework for defensive measures against credential exposure techniques.