CVE-2024-55578 in Zammad
Summary
by MITRE • 12/09/2024
Zammad before 6.4.1 places sensitive data (such as auth_microsoft_office365_credentials and application_secret) in log files.
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Analysis
by VulDB Data Team • 06/22/2025
This vulnerability in Zammad versions prior to 6.4.1 represents a critical security flaw that exposes sensitive authentication credentials in log files, creating significant risk for organizations relying on the platform for customer service and communication management. The issue stems from improper handling of sensitive data during logging operations, where authentication tokens and secret credentials are written to log files without adequate sanitization or protection measures. This behavior directly violates fundamental security principles and creates an attack surface that adversaries can exploit to gain unauthorized access to Microsoft Office 365 integrations and other authenticated services. The vulnerability affects the core logging functionality of the application, which is designed to capture operational data for troubleshooting and monitoring purposes but inadvertently includes confidential information that should never be persisted in plaintext within log repositories.
The technical implementation flaw occurs when Zammad processes authentication flows with Microsoft Office 365 services, where the system stores credential information in memory and subsequently logs this data as part of normal operational logging. This represents a classic case of insufficient input validation and output sanitization, where the application fails to properly filter or redact sensitive information before writing it to persistent storage. The vulnerability is classified as a logging security issue that falls under the broader category of information exposure, with potential implications for data integrity and confidentiality. According to CWE standards, this vulnerability aligns with CWE-209, which addresses the improper handling of sensitive information in log files, and CWE-532, which covers the insertion of sensitive information into log files. The flaw demonstrates poor separation of concerns in the application's security architecture, where authentication data flows directly into logging mechanisms without proper security controls.
The operational impact of this vulnerability extends far beyond simple credential exposure, as it enables adversaries to potentially compromise entire Microsoft Office 365 environments and access sensitive organizational data. Attackers who gain access to the log files can extract authentication tokens and secret credentials that allow them to impersonate legitimate users or access protected resources within the Office 365 ecosystem. This creates cascading security risks that can lead to data breaches, unauthorized access to email systems, and potential lateral movement within the network. The vulnerability also affects the platform's compliance with various regulatory frameworks such as gdpr, hipaa, and soc 2, as it creates unauthorized data exposure that violates data protection requirements. Organizations using Zammad for customer service management may face significant liability and reputation damage if this vulnerability is exploited, particularly in industries with strict data handling requirements.
Mitigation strategies for this vulnerability require immediate implementation of several security controls and configuration changes. Organizations should upgrade to Zammad version 6.4.1 or later, which includes proper credential sanitization in logging mechanisms. Additionally, system administrators must implement log file access controls, ensuring that only authorized personnel can access log repositories containing sensitive information. The application configuration should be reviewed to disable logging of authentication data or implement proper redaction mechanisms. Security monitoring should be enhanced to detect unauthorized access attempts to log files, and regular log file audits should be conducted to identify any remaining sensitive information. According to ATT&CK framework, this vulnerability maps to technique T1562.006, which covers "Taint Data", and T1078, which addresses "Valid Accounts". Organizations should also implement principle of least privilege access controls for log files, ensuring that log data is protected by appropriate file permissions and access controls. Regular security assessments and penetration testing should be conducted to verify that sensitive data is properly handled and that logging mechanisms do not inadvertently expose confidential information.